chore: sync mailcore v0.1.0-beta.1

mailcore/src/dns/mod.rs

@@ -0,0 +1,2 @@
+pub mod srv;
+pub use srv::discover_mail_server;

mailcore/src/dns/srv.rs

@@ -0,0 +1,108 @@
+use crate::types::MailServerConfig;
+use std::error::Error;
+use trust_dns_resolver::proto::rr::RecordType;
+use trust_dns_resolver::{
+    config::{ResolverConfig, ResolverOpts},
+    TokioAsyncResolver,
+};
+
+fn known_provider_config(domain: &str) -> Option<MailServerConfig> {
+    match domain {
+        "gmx.net" | "gmx.com" | "gmx.de" | "gmx.at" | "gmx.ch" => Some(MailServerConfig {
+            imap_host: format!("imap.{}", domain),
+            imap_port: 993,
+            smtp_host: format!("mail.{}", domain),
+            smtp_port: 587,
+        }),
+        "gmail.com" | "googlemail.com" => Some(MailServerConfig {
+            imap_host: "imap.gmail.com".to_string(),
+            imap_port: 993,
+            smtp_host: "smtp.gmail.com".to_string(),
+            smtp_port: 587,
+        }),
+        "yahoo.com" | "ymail.com" | "yahoo.co.uk" | "yahoo.co.in" => Some(MailServerConfig {
+            imap_host: "imap.mail.yahoo.com".to_string(),
+            imap_port: 993,
+            smtp_host: "smtp.mail.yahoo.com".to_string(),
+            smtp_port: 587,
+        }),
+        "outlook.com" | "hotmail.com" | "live.com" | "msn.com" => Some(MailServerConfig {
+            imap_host: "outlook.office365.com".to_string(),
+            imap_port: 993,
+            smtp_host: "smtp.office365.com".to_string(),
+            smtp_port: 587,
+        }),
+        "icloud.com" | "me.com" | "mac.com" => Some(MailServerConfig {
+            imap_host: "imap.mail.me.com".to_string(),
+            imap_port: 993,
+            smtp_host: "smtp.mail.me.com".to_string(),
+            smtp_port: 587,
+        }),
+        _ => None,
+    }
+}
+
+pub async fn discover_mail_server(email: &str) -> Result<MailServerConfig, Box<dyn Error>> {
+    let domain = email.split('@').nth(1).ok_or("Invalid email")?;
+
+    // Check well-known providers first to avoid slow DNS fallbacks
+    if let Some(config) = known_provider_config(domain) {
+        return Ok(config);
+    }
+
+    // Create async resolver
+    // Note: TokioAsyncResolver::tokio constructor is used for tokio runtime
+    let resolver = TokioAsyncResolver::tokio(ResolverConfig::default(), ResolverOpts::default());
+
+    // Try IMAPS SRV (_imaps._tcp.domain.com)
+    let imap_srv = format!("_imaps._tcp.{}", domain);
+    let imap_config = match resolver.lookup(&imap_srv, RecordType::SRV).await {
+        Ok(response) => {
+            let srv = response.iter().next().ok_or("No SRV records")?;
+            if let Some(srv_data) = srv.as_srv() {
+                (
+                    srv_data
+                        .target()
+                        .to_string()
+                        .trim_end_matches('.')
+                        .to_string(),
+                    srv_data.port(),
+                )
+            } else {
+                (domain.to_string(), 993) // Fallback
+            }
+        }
+        Err(_) => {
+            // No SRV, use standard port
+            (domain.to_string(), 993)
+        }
+    };
+
+    // Try SMTP Submission SRV (_submission._tcp.domain.com)
+    let smtp_srv = format!("_submission._tcp.{}", domain);
+    let smtp_config = match resolver.lookup(&smtp_srv, RecordType::SRV).await {
+        Ok(response) => {
+            let srv = response.iter().next().ok_or("No SRV records")?;
+            if let Some(srv_data) = srv.as_srv() {
+                (
+                    srv_data
+                        .target()
+                        .to_string()
+                        .trim_end_matches('.')
+                        .to_string(),
+                    srv_data.port(),
+                )
+            } else {
+                (domain.to_string(), 587) // Fallback
+            }
+        }
+        Err(_) => (domain.to_string(), 587),
+    };
+
+    Ok(MailServerConfig {
+        imap_host: imap_config.0,
+        imap_port: imap_config.1,
+        smtp_host: smtp_config.0,
+        smtp_port: smtp_config.1,
+    })
+}

mailcore/src/imap/mod.rs

@@ -0,0 +1,3 @@
+pub mod client;
+pub mod utf7;
+pub use client::ImapClient;

mailcore/src/imap/utf7.rs

@@ -0,0 +1,215 @@
+/// RFC 3501 modified UTF-7 decoder for IMAP mailbox names
+///
+/// Modified UTF-7 (RFC 3501) encoding rules:
+/// - Printable US-ASCII characters (0x20-0x7e, except "&") are represented by themselves
+/// - "&" is represented by "&-"
+/// - All other characters are represented as "&" + modified-BASE64(UTF-16BE) + "-"
+/// - Modified BASE64 uses "A-Za-z0-9,+" instead of "A-Za-z0-9+/"
+
+pub fn decode_modified_utf7(encoded: &str) -> String {
+    let bytes = encoded.as_bytes();
+    let mut result = String::new();
+    let mut i = 0;
+
+    while i < bytes.len() {
+        let byte = bytes[i];
+
+        // Printable ASCII (except '&') - pass through
+        if byte != b'&' && byte >= 0x20 && byte <= 0x7e {
+            result.push(byte as char);
+            i += 1;
+            continue;
+        }
+
+        // "&" starts a sequence
+        if byte == b'&' {
+            if i + 1 < bytes.len() && bytes[i + 1] == b'-' {
+                // "&-" represents literal "&"
+                result.push('&');
+                i += 2;
+                continue;
+            }
+
+            // Find the closing "-"
+            let mut j = i + 1;
+            while j < bytes.len() && bytes[j] != b'-' {
+                j += 1;
+            }
+
+            if j >= bytes.len() {
+                // Malformed: no closing "-", treat as literal
+                result.push('&');
+                i += 1;
+                continue;
+            }
+
+            // Extract the modified-BASE64 sequence
+            let b64_str = std::str::from_utf8(&bytes[i + 1..j]).unwrap_or("");
+
+            // Decode modified-BASE64 (replace "," with "/")
+            let b64_std = b64_str.replace(',', "/");
+
+            // Decode from standard BASE64
+            if let Ok(decoded_bytes) = base64_decode(&b64_std) {
+                // Convert UTF-16BE bytes to UTF-16 chars, then to UTF-8
+                if let Ok(text) = decode_utf16be(&decoded_bytes) {
+                    result.push_str(&text);
+                } else {
+                    // Invalid UTF-16, use replacement character
+                    result.push('\u{FFFD}');
+                }
+            } else {
+                // Invalid BASE64, use replacement character
+                result.push('\u{FFFD}');
+            }
+
+            i = j + 1;
+            continue;
+        }
+
+        // Other bytes (shouldn't happen in valid UTF-7)
+        result.push('\u{FFFD}');
+        i += 1;
+    }
+
+    result
+}
+
+/// Decode standard BASE64 (RFC 4648)
+fn base64_decode(input: &str) -> Result<Vec<u8>, String> {
+    const TABLE: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+    let mut result = Vec::new();
+    let input = input.as_bytes();
+    let mut i = 0;
+
+    while i < input.len() {
+        let mut buf = [0u8; 4];
+        let mut len = 0;
+
+        // Read up to 4 base64 characters
+        while len < 4 && i < input.len() {
+            let b = input[i];
+            if b == b'=' {
+                break;
+            }
+            if let Some(pos) = TABLE.iter().position(|&x| x == b) {
+                buf[len] = pos as u8;
+                len += 1;
+            } else if !b.is_ascii_whitespace() {
+                return Err("Invalid base64 character".to_string());
+            }
+            i += 1;
+        }
+
+        // Decode the 4-character group
+        match len {
+            0 => break,
+            1 => return Err("Invalid base64 length".to_string()),
+            2 => {
+                result.push(((buf[0] << 2) | (buf[1] >> 4)) as u8);
+            }
+            3 => {
+                result.push(((buf[0] << 2) | (buf[1] >> 4)) as u8);
+                result.push((((buf[1] & 0x0f) << 4) | (buf[2] >> 2)) as u8);
+            }
+            4 => {
+                result.push(((buf[0] << 2) | (buf[1] >> 4)) as u8);
+                result.push((((buf[1] & 0x0f) << 4) | (buf[2] >> 2)) as u8);
+                result.push((((buf[2] & 0x03) << 6) | buf[3]) as u8);
+            }
+            _ => return Err("Invalid base64 length".to_string()),
+        }
+
+        // Skip padding
+        while i < input.len() && input[i] == b'=' {
+            i += 1;
+        }
+    }
+
+    Ok(result)
+}
+
+/// Decode UTF-16BE bytes to UTF-8 string
+fn decode_utf16be(bytes: &[u8]) -> Result<String, String> {
+    if bytes.len() % 2 != 0 {
+        return Err("Odd number of bytes in UTF-16BE sequence".to_string());
+    }
+
+    let mut chars = Vec::new();
+    let mut i = 0;
+
+    while i < bytes.len() {
+        let high = u16::from_be_bytes([bytes[i], bytes[i + 1]]);
+        i += 2;
+
+        // Check for surrogate pair
+        if (high & 0xFC00) == 0xD800 {
+            // High surrogate, expect low surrogate
+            if i + 2 > bytes.len() {
+                chars.push('\u{FFFD}');
+                break;
+            }
+            let low = u16::from_be_bytes([bytes[i], bytes[i + 1]]);
+            i += 2;
+
+            if (low & 0xFC00) != 0xDC00 {
+                chars.push('\u{FFFD}');
+                continue;
+            }
+
+            // Decode surrogate pair
+            let high_bits = (high & 0x3FF) as u32;
+            let low_bits = (low & 0x3FF) as u32;
+            let codepoint = 0x10000 + (high_bits << 10) + low_bits;
+
+            if let Some(ch) = char::from_u32(codepoint) {
+                chars.push(ch);
+            } else {
+                chars.push('\u{FFFD}');
+            }
+        } else if (high & 0xFC00) == 0xDC00 {
+            // Unexpected low surrogate
+            chars.push('\u{FFFD}');
+        } else {
+            // Regular BMP character
+            if let Some(ch) = char::from_u32(high as u32) {
+                chars.push(ch);
+            } else {
+                chars.push('\u{FFFD}');
+            }
+        }
+    }
+
+    Ok(chars.iter().collect())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_ascii_passthrough() {
+        assert_eq!(decode_modified_utf7("INBOX"), "INBOX");
+        assert_eq!(decode_modified_utf7("Sent Mail"), "Sent Mail");
+        assert_eq!(decode_modified_utf7("Drafts"), "Drafts");
+    }
+
+    #[test]
+    fn test_literal_ampersand() {
+        assert_eq!(decode_modified_utf7("A&-B"), "A&B");
+        assert_eq!(decode_modified_utf7("&-"), "&");
+    }
+
+    #[test]
+    fn test_mixed_ascii_and_encoded() {
+        // Test that ASCII parts pass through while encoded parts are decoded
+        // This is a basic test to ensure the structure works
+        assert!(decode_modified_utf7("Folder&-Name").contains("&"));
+    }
+
+    #[test]
+    fn test_decode_empty() {
+        assert_eq!(decode_modified_utf7(""), "");
+    }
+}

mailcore/src/lib.rs

@@ -0,0 +1,13 @@
+#![allow(unexpected_cfgs)]
+pub mod api;
+pub mod dns;
+pub mod imap;
+pub mod mime;
+pub mod secrets;
+pub mod smtp;
+pub mod storage;
+pub mod types;
+
+// Re-export specific items if needed
+pub use types::MailServerConfig;
+pub mod session_manager;

mailcore/src/mime/mod.rs

@@ -0,0 +1 @@
+// MIME module placeholder

mailcore/src/session_manager.rs

@@ -0,0 +1,112 @@
+use crate::imap::ImapClient;
+use crate::types::MailServerConfig;
+use lazy_static::lazy_static;
+use std::collections::HashMap;
+use std::sync::Arc;
+use tokio::sync::Mutex;
+
+lazy_static! {
+    /// A global map of active IMAP sessions, keyed by email address.
+    /// Each session is wrapped in an Arc<Mutex> to allow safe concurrent access (though IMAP is largely sequential).
+    static ref SESSIONS: Arc<Mutex<HashMap<String, Arc<Mutex<ImapClient>>>>> = Arc::new(Mutex::new(HashMap::new()));
+}
+
+/// Retrieves an existing active session or creates a new one.
+/// If an existing session is found but disconnected, it attempts to reconnect.
+pub async fn get_client(
+    config: MailServerConfig,
+    email: String,
+    password: String,
+) -> Result<Arc<Mutex<ImapClient>>, crate::types::MailError> {
+    // Atomic get-or-insert to avoid race conditions on startup
+    let (client_arc, is_new) = {
+        let mut sessions = SESSIONS.lock().await;
+        if let Some(arc) = sessions.get(&email) {
+            (arc.clone(), false)
+        } else {
+            let client = ImapClient::new(config, email.clone());
+            let arc = Arc::new(Mutex::new(client));
+            sessions.insert(email.clone(), arc.clone());
+            (arc, true)
+        }
+    };
+
+    let mut client = client_arc.lock().await;
+
+    if is_new {
+        tracing::debug!(
+            "SyncManager: Establishing new IMAP connection for {}...",
+            email
+        );
+        if let Err(e) = tokio::time::timeout(
+            std::time::Duration::from_secs(20),
+            client.connect(&password),
+        )
+        .await
+        .unwrap_or_else(|_| Err("Connection timeout".into()))
+        {
+            let err_msg = e.to_string();
+            // Critical cleanup: Remove failed shell so it can be retried later
+            {
+                let mut sessions = SESSIONS.lock().await;
+                sessions.remove(&email);
+            }
+            if err_msg.to_lowercase().contains("auth")
+                || err_msg.to_lowercase().contains("login")
+                || err_msg.to_lowercase().contains("credentials")
+            {
+                return Err(crate::types::MailError::Auth(err_msg));
+            } else {
+                return Err(crate::types::MailError::Network(err_msg));
+            }
+        }
+    } else {
+        // Double-check connection health
+        if !tokio::time::timeout(std::time::Duration::from_secs(5), client.keep_alive())
+            .await
+            .unwrap_or(false)
+        {
+            tracing::debug!(
+                "SyncManager: Connection for {} is dead, attempting reconnect...",
+                email
+            );
+            if let Err(e) = tokio::time::timeout(
+                std::time::Duration::from_secs(15),
+                client.reconnect(&password),
+            )
+            .await
+            .unwrap_or_else(|_| Err("Reconnect timeout".into()))
+            {
+                tracing::error!("SyncManager: Reconnect failed for {}: {}", email, e);
+                // Remove the stale entry so the next call creates a fresh connection
+                // instead of looping on keep_alive() against a broken session.
+                drop(client);
+                let mut sessions = SESSIONS.lock().await;
+                sessions.remove(&email);
+                return Err(crate::types::MailError::Network(e.to_string()));
+            }
+        }
+    }
+
+    Ok(client_arc.clone())
+}
+
+/// Disconnects and removes a session from the manager.
+pub async fn logout(email: &str) {
+    let mut sessions = SESSIONS.lock().await;
+    if let Some(client_arc) = sessions.remove(email) {
+        let mut client = client_arc.lock().await;
+        let _ = client.logout().await;
+        tracing::debug!("Logged out session for {}", email);
+    }
+}
+
+/// Checks if a session exists and is alive for the given email.
+pub async fn is_connected(email: &str) -> bool {
+    let sessions = SESSIONS.lock().await;
+    if let Some(client_arc) = sessions.get(email) {
+        let mut client = client_arc.lock().await;
+        return client.keep_alive().await;
+    }
+    false
+}

mailcore/src/smtp/client.rs

@@ -0,0 +1,120 @@
+use crate::types::MailServerConfig;
+use lettre::message::{MultiPart, SinglePart};
+use lettre::{Message, SmtpTransport, Transport};
+use std::error::Error;
+
+pub struct SmtpClient {
+    config: MailServerConfig,
+    email: String,
+}
+
+impl SmtpClient {
+    pub fn new(config: MailServerConfig, email: String) -> Self {
+        Self { config, email }
+    }
+
+    pub async fn send_mail(
+        &self,
+        password: &str,
+        to: &str,
+        subject: &str,
+        body_text: &str,
+        attachments: Vec<crate::types::Attachment>,
+    ) -> Result<Vec<u8>, Box<dyn Error>> {
+        let mut builder = Message::builder()
+            .from(self.email.parse()?)
+            .subject(subject);
+        for addr in to.split(',') {
+            builder = builder.to(addr.trim().parse()?);
+        }
+
+        let email = if attachments.is_empty() {
+            builder.singlepart(SinglePart::plain(body_text.to_string()))?
+        } else {
+            let mut multipart =
+                MultiPart::mixed().singlepart(SinglePart::plain(body_text.to_string()));
+
+            for att in attachments {
+                multipart = multipart.singlepart(
+                    SinglePart::builder()
+                        .header(lettre::message::header::ContentType::parse(
+                            &att.content_type,
+                        )?)
+                        .header(lettre::message::header::ContentDisposition::attachment(
+                            &att.name,
+                        ))
+                        .body(att.content),
+                );
+            }
+            builder.multipart(multipart)?
+        };
+
+        use lettre::transport::smtp::client::{Tls, TlsParameters};
+
+        let creds = lettre::transport::smtp::authentication::Credentials::new(
+            self.email.clone(),
+            password.to_string(),
+        );
+
+        let tls_parameters = TlsParameters::new(self.config.smtp_host.clone())?;
+
+        // Explicitly choose TLS mode based on port
+        let tls = if self.config.smtp_port == 465 {
+            Tls::Wrapper(tls_parameters)
+        } else {
+            Tls::Opportunistic(tls_parameters)
+        };
+
+        let mailer = SmtpTransport::builder_dangerous(&self.config.smtp_host)
+            .port(self.config.smtp_port)
+            .tls(tls)
+            .credentials(creds)
+            .build();
+
+        let raw_bytes = email.formatted();
+        mailer.send(&email)?;
+
+        Ok(raw_bytes)
+    }
+
+    pub async fn send_raw_mail(
+        &self,
+        password: &str,
+        to: &str,
+        _subject: &str,
+        raw_message: &[u8],
+    ) -> Result<(), Box<dyn Error>> {
+        use lettre::transport::smtp::client::{Tls, TlsParameters};
+
+        let creds = lettre::transport::smtp::authentication::Credentials::new(
+            self.email.clone(),
+            password.to_string(),
+        );
+
+        let tls_parameters = TlsParameters::new(self.config.smtp_host.clone())?;
+
+        let tls = if self.config.smtp_port == 465 {
+            Tls::Wrapper(tls_parameters)
+        } else {
+            Tls::Opportunistic(tls_parameters)
+        };
+
+        let mailer = SmtpTransport::builder_dangerous(&self.config.smtp_host)
+            .port(self.config.smtp_port)
+            .tls(tls)
+            .credentials(creds)
+            .build();
+
+        // Build a manual message from raw bytes; `to` may be comma-separated
+        let recipients: Vec<lettre::address::Address> = to
+            .split(',')
+            .map(|addr| addr.trim().parse())
+            .collect::<Result<Vec<_>, _>>()?;
+        let envelope =
+            lettre::address::Envelope::new(Some(self.email.parse()?), recipients)?;
+
+        mailer.send_raw(&envelope, raw_message)?;
+
+        Ok(())
+    }
+}

mailcore/src/smtp/mod.rs

@@ -0,0 +1,2 @@
+pub mod client;
+pub use client::SmtpClient;

mailcore/src/storage/mod.rs

@@ -0,0 +1,733 @@
+use crate::types::{Draft, MessageHeader, PgpStatus};
+use rusqlite::{params, Connection, OptionalExtension};
+use std::error::Error;
+
+pub struct Storage {
+    path: String,
+}
+
+impl Storage {
+    pub fn new(path: &str) -> Result<Self, Box<dyn Error + Send + Sync>> {
+        let conn = Connection::open(path)?;
+
+        // Enable WAL mode for concurrent read/write access.
+        conn.execute_batch("PRAGMA journal_mode=WAL;")?;
+
+        // Set a 5-second busy timeout.
+        conn.busy_timeout(std::time::Duration::from_secs(5))?;
+
+        // New messages table with folder support
+        conn.execute(
+            "CREATE TABLE IF NOT EXISTS messages_v2 (
+                folder TEXT,
+                uid INTEGER,
+                subject TEXT,
+                sender TEXT,
+                recipients TEXT,
+                date INTEGER,
+                is_read INTEGER,
+                has_attachments INTEGER,
+                pgp_status TEXT,
+                flag TEXT,
+                PRIMARY KEY (folder, uid)
+            )",
+            [],
+        )?;
+
+        // Message bodies table for full offline cache
+        conn.execute(
+            "CREATE TABLE IF NOT EXISTS message_bodies (
+                folder TEXT,
+                uid INTEGER,
+                raw_content BLOB,
+                PRIMARY KEY (folder, uid)
+            )",
+            [],
+        )?;
+
+        conn.execute(
+            "CREATE TABLE IF NOT EXISTS contacts (
+                email TEXT PRIMARY KEY,
+                display_name TEXT,
+                public_key TEXT,
+                fingerprint TEXT,
+                trust_level TEXT DEFAULT 'Unknown',
+                first_seen INTEGER,
+                last_seen INTEGER
+            )",
+            [],
+        )?;
+
+        // Migrations for existing databases
+        let _ = conn.execute(
+            "ALTER TABLE messages_v2 ADD COLUMN recipients TEXT DEFAULT '[]'",
+            [],
+        );
+        let _ = conn.execute(
+            "ALTER TABLE messages_v2 ADD COLUMN is_read INTEGER DEFAULT 0",
+            [],
+        );
+        let _ = conn.execute(
+            "ALTER TABLE messages_v2 ADD COLUMN has_attachments INTEGER DEFAULT 0",
+            [],
+        );
+        let _ = conn.execute(
+            "ALTER TABLE messages_v2 ADD COLUMN pgp_status TEXT DEFAULT 'None'",
+            [],
+        );
+        let _ = conn.execute("ALTER TABLE contacts ADD COLUMN fingerprint TEXT", []);
+        let _ = conn.execute(
+            "ALTER TABLE contacts ADD COLUMN trust_level TEXT DEFAULT 'Unknown'",
+            [],
+        );
+        let _ = conn.execute("ALTER TABLE contacts ADD COLUMN first_seen INTEGER", []);
+        let _ = conn.execute("ALTER TABLE contacts ADD COLUMN last_seen INTEGER", []);
+        let _ = conn.execute("ALTER TABLE messages_v2 ADD COLUMN flag TEXT", []);
+        let _ = conn.execute(
+            "ALTER TABLE sync_state ADD COLUMN server_total INTEGER NOT NULL DEFAULT 0",
+            [],
+        );
+
+        // sync_state table
+        conn.execute(
+            "CREATE TABLE IF NOT EXISTS sync_state (
+                account TEXT,
+                folder TEXT,
+                uidvalidity INTEGER,
+                last_uid INTEGER,
+                PRIMARY KEY (account, folder)
+            )",
+            [],
+        )?;
+
+        // Normalize INBOX
+        let _ = conn.execute(
+            "UPDATE messages_v2 SET folder = 'INBOX' WHERE LOWER(folder) = 'inbox' AND folder != 'INBOX'",
+            [],
+        );
+        let _ = conn.execute(
+            "UPDATE message_bodies SET folder = 'INBOX' WHERE LOWER(folder) = 'inbox' AND folder != 'INBOX'",
+            [],
+        );
+        let _ = conn.execute(
+            "UPDATE sync_state SET folder = 'INBOX' WHERE LOWER(folder) = 'inbox' AND folder != 'INBOX'",
+            [],
+        );
+
+        conn.execute(
+            "CREATE TABLE IF NOT EXISTS pgp_identities (
+                fingerprint TEXT PRIMARY KEY,
+                email TEXT,
+                public_key TEXT,
+                private_key TEXT
+            )",
+            [],
+        )?;
+
+        conn.execute(
+            "CREATE TABLE IF NOT EXISTS drafts (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                recipient TEXT,
+                subject TEXT,
+                body TEXT,
+                last_updated INTEGER,
+                last_synced_at INTEGER DEFAULT 0,
+                server_uid INTEGER
+            )",
+            [],
+        )?;
+
+        conn.execute(
+            "CREATE TABLE IF NOT EXISTS draft_attachments (
+                draft_id INTEGER,
+                name TEXT,
+                content_type TEXT,
+                content BLOB,
+                FOREIGN KEY (draft_id) REFERENCES drafts(id) ON DELETE CASCADE
+            )",
+            [],
+        )?;
+
+        Ok(Storage {
+            path: path.to_string(),
+        })
+    }
+
+    fn connect(&self) -> Result<Connection, Box<dyn Error + Send + Sync>> {
+        Ok(Connection::open(&self.path)?)
+    }
+
+    pub fn save_draft(&self, draft: &Draft) -> Result<i64, Box<dyn Error + Send + Sync>> {
+        let mut conn = self.connect()?;
+        let tx = conn.transaction()?;
+
+        let draft_id = if let Some(id) = draft.id {
+            tx.execute(
+                "UPDATE drafts SET recipient = ?1, subject = ?2, body = ?3, last_updated = ?4, last_synced_at = ?5, server_uid = ?6 WHERE id = ?7",
+                params![draft.to, draft.subject, draft.body, draft.last_updated, draft.last_synced_at, draft.server_uid, id],
+            )?;
+            id
+        } else {
+            tx.execute(
+                "INSERT INTO drafts (recipient, subject, body, last_updated, last_synced_at, server_uid) VALUES (?1, ?2, ?3, ?4, ?5, ?6)",
+                params![draft.to, draft.subject, draft.body, draft.last_updated, draft.last_synced_at, draft.server_uid],
+            )?;
+            tx.last_insert_rowid()
+        };
+
+        // Update attachments
+        tx.execute(
+            "DELETE FROM draft_attachments WHERE draft_id = ?1",
+            params![draft_id],
+        )?;
+        for att in &draft.attachments {
+            tx.execute(
+                "INSERT INTO draft_attachments (draft_id, name, content_type, content) VALUES (?1, ?2, ?3, ?4)",
+                params![draft_id, att.name, att.content_type, att.content],
+            )?;
+        }
+
+        tx.commit()?;
+        Ok(draft_id)
+    }
+
+    pub fn get_drafts(&self) -> Result<Vec<Draft>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt = conn
+            .prepare("SELECT id, recipient, subject, body, last_updated, last_synced_at, server_uid FROM drafts")?;
+        let rows = stmt.query_map([], |row| {
+            let id: i64 = row.get(0)?;
+
+            // Load attachments for this draft
+            let mut att_stmt = conn.prepare(
+                "SELECT name, content_type, content FROM draft_attachments WHERE draft_id = ?1",
+            )?;
+            let att_rows = att_stmt.query_map(params![id], |att_row| {
+                let content: Vec<u8> = att_row.get(2)?;
+                let size = content.len();
+                Ok(crate::types::Attachment {
+                    name: att_row.get(0)?,
+                    content_type: att_row.get(1)?,
+                    size,
+                    content,
+                })
+            })?;
+
+            let mut attachments = Vec::new();
+            for att in att_rows {
+                attachments.push(att?);
+            }
+
+            Ok(Draft {
+                id: Some(id),
+                to: row.get(1)?,
+                subject: row.get(2)?,
+                body: row.get(3)?,
+                attachments,
+                last_updated: row.get(4).unwrap_or(0),
+                last_synced_at: row.get(5).unwrap_or(0),
+                server_uid: row.get(6).ok(),
+            })
+        })?;
+
+        let mut drafts = Vec::new();
+        for draft in rows {
+            drafts.push(draft?);
+        }
+        Ok(drafts)
+    }
+
+    pub fn delete_draft(&self, id: i64) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute("DELETE FROM drafts WHERE id = ?1", params![id])?;
+        Ok(())
+    }
+
+    pub fn save_header(
+        &self,
+        folder: &str,
+        header: &MessageHeader,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let recipients_json =
+            serde_json::to_string(&header.to).unwrap_or_else(|_| "[]".to_string());
+
+        conn.execute(
+            "INSERT OR REPLACE INTO messages_v2 (folder, uid, subject, sender, recipients, date, is_read, has_attachments, pgp_status, flag)
+             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10)",
+            params![
+                folder,
+                header.uid,
+                header.subject,
+                header.from,
+                recipients_json,
+                header.date,
+                if header.is_read { 1 } else { 0 },
+                if header.has_attachments { 1 } else { 0 },
+                format!("{:?}", header.pgp_status),
+                header.flag.clone(),
+            ],
+        )?;
+        Ok(())
+    }
+
+    pub fn get_uids(
+        &self,
+        folder: &str,
+    ) -> Result<std::collections::HashSet<u32>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt = conn.prepare("SELECT uid FROM messages_v2 WHERE folder = ?1")?;
+        let rows = stmt.query_map(rusqlite::params![folder], |row| row.get::<_, u32>(0))?;
+
+        let mut uids = std::collections::HashSet::new();
+        for uid in rows {
+            if let Ok(u) = uid {
+                uids.insert(u);
+            }
+        }
+        Ok(uids)
+    }
+
+    pub fn get_headers(
+        &self,
+        folder: &str,
+    ) -> Result<Vec<MessageHeader>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt = conn.prepare("SELECT uid, subject, sender, recipients, date, is_read, has_attachments, pgp_status, flag FROM messages_v2 WHERE folder = ?1 ORDER BY date DESC")?;
+        let rows = stmt.query_map(params![folder], |row| {
+            let recipients_json: String = row.get(3)?;
+            let to: Vec<String> = serde_json::from_str(&recipients_json).unwrap_or_default();
+            let pgp_status_str: String = row.get(7)?;
+
+            let pgp_status = match pgp_status_str.as_str() {
+                "Encrypted" => PgpStatus::Encrypted,
+                "Signed" => PgpStatus::Signed,
+                "SignedAndEncrypted" => PgpStatus::SignedAndEncrypted,
+                "InvalidSignature" => PgpStatus::InvalidSignature,
+                "EncryptedAtRest" => PgpStatus::EncryptedAtRest,
+                _ => PgpStatus::None,
+            };
+
+            Ok(MessageHeader {
+                uid: row.get(0)?,
+                subject: row.get(1)?,
+                from: row.get(2)?,
+                to,
+                date: row.get(4)?,
+                is_read: row.get::<_, i32>(5)? == 1,
+                has_attachments: row.get::<_, i32>(6)? == 1,
+                pgp_status,
+                flag: row.get(8).unwrap_or(None),
+            })
+        })?;
+
+        let mut headers = Vec::new();
+        for header in rows {
+            headers.push(header?);
+        }
+        Ok(headers)
+    }
+
+    pub fn delete_header(
+        &self,
+        folder: &str,
+        uid: u32,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "DELETE FROM messages_v2 WHERE folder = ?1 AND uid = ?2",
+            params![folder, uid],
+        )?;
+        conn.execute(
+            "DELETE FROM message_bodies WHERE folder = ?1 AND uid = ?2",
+            params![folder, uid],
+        )?;
+        Ok(())
+    }
+
+    pub fn delete_headers(
+        &self,
+        folder: &str,
+        uids: &[u32],
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        if uids.is_empty() {
+            return Ok(());
+        }
+        let conn = self.connect()?;
+        let placeholders = (0..uids.len())
+            .map(|i| format!("?{}", i + 2))
+            .collect::<Vec<_>>()
+            .join(",");
+        let sql_messages = format!(
+            "DELETE FROM messages_v2 WHERE folder = ?1 AND uid IN ({})",
+            placeholders
+        );
+        let sql_bodies = format!(
+            "DELETE FROM message_bodies WHERE folder = ?1 AND uid IN ({})",
+            placeholders
+        );
+        {
+            let mut stmt = conn.prepare(&sql_messages)?;
+            let mut p: Vec<Box<dyn rusqlite::ToSql>> = Vec::with_capacity(uids.len() + 1);
+            p.push(Box::new(folder.to_string()));
+            for &uid in uids {
+                p.push(Box::new(uid));
+            }
+            let refs: Vec<&dyn rusqlite::ToSql> = p.iter().map(|v| v.as_ref()).collect();
+            stmt.execute(refs.as_slice())?;
+        }
+        {
+            let mut stmt = conn.prepare(&sql_bodies)?;
+            let mut p: Vec<Box<dyn rusqlite::ToSql>> = Vec::with_capacity(uids.len() + 1);
+            p.push(Box::new(folder.to_string()));
+            for &uid in uids {
+                p.push(Box::new(uid));
+            }
+            let refs: Vec<&dyn rusqlite::ToSql> = p.iter().map(|v| v.as_ref()).collect();
+            stmt.execute(refs.as_slice())?;
+        }
+        Ok(())
+    }
+
+    pub fn wipe_folder(&self, folder: &str) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute("DELETE FROM messages_v2 WHERE folder = ?1", params![folder])?;
+        conn.execute(
+            "DELETE FROM message_bodies WHERE folder = ?1",
+            params![folder],
+        )?;
+        Ok(())
+    }
+
+    pub fn update_read_status(
+        &self,
+        folder: &str,
+        uid: u32,
+        is_read: bool,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "UPDATE messages_v2 SET is_read = ?1 WHERE folder = ?2 AND uid = ?3",
+            params![if is_read { 1 } else { 0 }, folder, uid],
+        )?;
+        Ok(())
+    }
+
+    pub fn mark_all_as_read(&self, folder: &str) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "UPDATE messages_v2 SET is_read = 1 WHERE folder = ?1",
+            params![folder],
+        )?;
+        Ok(())
+    }
+
+    pub fn update_message_flag(
+        &self,
+        folder: &str,
+        uid: u32,
+        flag: Option<String>,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "UPDATE messages_v2 SET flag = ?1 WHERE folder = ?2 AND uid = ?3",
+            params![flag, folder, uid],
+        )?;
+        Ok(())
+    }
+
+    pub fn save_message_raw(
+        &self,
+        folder: &str,
+        uid: u32,
+        content: &[u8],
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "INSERT OR REPLACE INTO message_bodies (folder, uid, raw_content) VALUES (?1, ?2, ?3)",
+            params![folder, uid, content],
+        )?;
+        Ok(())
+    }
+
+    pub fn get_message_raw(
+        &self,
+        folder: &str,
+        uid: u32,
+    ) -> Result<Option<Vec<u8>>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt =
+            conn.prepare("SELECT raw_content FROM message_bodies WHERE folder = ?1 AND uid = ?2")?;
+        let result = stmt
+            .query_row(params![folder, uid], |row| row.get(0))
+            .optional()?;
+        Ok(result)
+    }
+
+    pub fn save_contact(
+        &self,
+        contact: &crate::types::Contact,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "INSERT OR IGNORE INTO contacts (email, display_name, public_key, fingerprint, trust_level, first_seen, last_seen) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)",
+            params![
+                contact.email.to_lowercase(),
+                contact.display_name,
+                contact.public_key,
+                contact.fingerprint,
+                format!("{:?}", contact.trust_level),
+                contact.first_seen,
+                contact.last_seen
+            ],
+        )?;
+        Ok(())
+    }
+
+    pub fn get_contacts(&self) -> Result<Vec<crate::types::Contact>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt = conn.prepare(
+            "SELECT email, display_name, public_key, fingerprint, trust_level, first_seen, last_seen FROM contacts",
+        )?;
+        let rows = stmt.query_map([], |row| {
+            let trust_level_str: String = row.get(4)?;
+            let trust_level = match trust_level_str.as_str() {
+                "Trusted" => crate::types::TrustLevel::Trusted,
+                "Established" => crate::types::TrustLevel::Established,
+                "Warning" => crate::types::TrustLevel::Warning,
+                _ => crate::types::TrustLevel::Unknown,
+            };
+
+            Ok(crate::types::Contact {
+                email: row.get(0)?,
+                display_name: row.get(1)?,
+                public_key: row.get(2)?,
+                fingerprint: row.get(3)?,
+                trust_level,
+                first_seen: row.get(5).unwrap_or(0),
+                last_seen: row.get(6).unwrap_or(0),
+            })
+        })?;
+
+        let mut contacts = Vec::new();
+        for contact in rows {
+            contacts.push(contact?);
+        }
+        Ok(contacts)
+    }
+
+    pub fn get_contact_by_email(
+        &self,
+        email: &str,
+    ) -> Result<Option<crate::types::Contact>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt =
+            conn.prepare("SELECT email, display_name, public_key, fingerprint, trust_level, first_seen, last_seen FROM contacts WHERE LOWER(email) = LOWER(?1)")?;
+        let contact = stmt.query_row(params![email.to_lowercase()], |row| {
+            let trust_level_str: String = row.get(4)?;
+            let trust_level = match trust_level_str.as_str() {
+                "Trusted" => crate::types::TrustLevel::Trusted,
+                "Established" => crate::types::TrustLevel::Established,
+                "Warning" => crate::types::TrustLevel::Warning,
+                _ => crate::types::TrustLevel::Unknown,
+            };
+
+            Ok(crate::types::Contact {
+                email: row.get(0)?,
+                display_name: row.get(1)?,
+                public_key: row.get(2)?,
+                fingerprint: row.get(3)?,
+                trust_level,
+                first_seen: row.get(5).unwrap_or(0),
+                last_seen: row.get(6).unwrap_or(0),
+            })
+        });
+
+        match contact {
+            Ok(c) => Ok(Some(c)),
+            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
+            Err(e) => Err(e.into()),
+        }
+    }
+
+    pub fn delete_contact(&self, email: &str) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "DELETE FROM contacts WHERE LOWER(email) = LOWER(?1)",
+            params![email.to_lowercase()],
+        )?;
+        Ok(())
+    }
+
+    pub fn save_identity(
+        &self,
+        email: &str,
+        keypair: &crate::types::PgpKeyPair,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "INSERT OR REPLACE INTO pgp_identities (fingerprint, email, public_key, private_key) VALUES (?1, ?2, ?3, ?4)",
+            params![keypair.fingerprint, email.to_lowercase(), keypair.public_key, keypair.private_key],
+        )?;
+        Ok(())
+    }
+
+    pub fn list_identities(
+        &self,
+        email: &str,
+    ) -> Result<Vec<crate::types::PgpKeyPair>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt = conn.prepare(
+            "SELECT public_key, private_key, fingerprint FROM pgp_identities WHERE LOWER(email) = LOWER(?1)",
+        )?;
+        let rows = stmt.query_map(params![email.to_lowercase()], |row| {
+            let pub_key: String = row.get(0)?;
+            let priv_key: String = row.get(1)?;
+            let fingerprint: String = row.get(2)?;
+
+            Ok(crate::types::PgpKeyPair {
+                public_key: pub_key,
+                private_key: priv_key,
+                key_info: format!("Key: {}", fingerprint),
+                fingerprint,
+                user_ids: Vec::new(),
+            })
+        })?;
+
+        let mut identities = Vec::new();
+        for id in rows {
+            identities.push(id?);
+        }
+        Ok(identities)
+    }
+
+    pub fn get_identity_by_fingerprint(
+        &self,
+        fingerprint: &str,
+    ) -> Result<Option<crate::types::PgpKeyPair>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt =
+            conn.prepare("SELECT public_key, private_key, fingerprint FROM pgp_identities WHERE fingerprint = ?1")?;
+        let keypair = stmt.query_row(params![fingerprint], |row| {
+            let pub_key: String = row.get(0)?;
+            let priv_key: String = row.get(1)?;
+            let fingerprint: String = row.get(2)?;
+
+            Ok(crate::types::PgpKeyPair {
+                public_key: pub_key,
+                private_key: priv_key,
+                key_info: format!("Key: {}", fingerprint),
+                fingerprint,
+                user_ids: Vec::new(),
+            })
+        });
+
+        match keypair {
+            Ok(k) => Ok(Some(k)),
+            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(None),
+            Err(e) => Err(e.into()),
+        }
+    }
+
+    pub fn delete_identity(&self, fingerprint: &str) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "DELETE FROM pgp_identities WHERE fingerprint = ?1",
+            params![fingerprint],
+        )?;
+        Ok(())
+    }
+
+    pub fn update_sync_state(
+        &self,
+        account: &str,
+        folder: &str,
+        uidvalidity: u32,
+        last_uid: u32,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "INSERT OR REPLACE INTO sync_state (account, folder, uidvalidity, last_uid) VALUES (?1, ?2, ?3, ?4)",
+            params![account, folder, uidvalidity, last_uid],
+        )?;
+        Ok(())
+    }
+
+    pub fn get_sync_state(
+        &self,
+        account: &str,
+        folder: &str,
+    ) -> Result<Option<(u32, u32)>, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let mut stmt = conn.prepare(
+            "SELECT uidvalidity, last_uid FROM sync_state WHERE account = ?1 AND folder = ?2",
+        )?;
+
+        let mut rows = stmt.query(params![account, folder])?;
+
+        if let Some(row) = rows.next()? {
+            Ok(Some((row.get(0)?, row.get(1)?)))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub fn get_unread_count(&self, folder: &str) -> Result<i32, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let count: i32 = conn.query_row(
+            "SELECT COUNT(*) FROM messages_v2 WHERE folder = ?1 AND is_read = 0",
+            params![folder],
+            |row| row.get(0),
+        )?;
+        Ok(count)
+    }
+
+    pub fn update_server_total(
+        &self,
+        account: &str,
+        folder: &str,
+        total: u32,
+    ) -> Result<(), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        conn.execute(
+            "INSERT OR IGNORE INTO sync_state (account, folder, uidvalidity, last_uid, server_total) VALUES (?1, ?2, 0, 0, 0)",
+            params![account, folder],
+        )?;
+        conn.execute(
+            "UPDATE sync_state SET server_total = ?3 WHERE account = ?1 AND folder = ?2",
+            params![account, folder, total],
+        )?;
+        Ok(())
+    }
+
+    pub fn get_folder_stats(
+        &self,
+        account: &str,
+        folder: &str,
+    ) -> Result<(i32, i32), Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let unread: i32 = conn.query_row(
+            "SELECT COUNT(*) FROM messages_v2 WHERE folder = ?1 AND is_read = 0",
+            params![folder],
+            |row| row.get(0),
+        )?;
+        let server_total: i32 = conn
+            .query_row(
+                "SELECT COALESCE(server_total, 0) FROM sync_state WHERE account = ?1 AND folder = ?2",
+                params![account, folder],
+                |row| row.get(0),
+            )
+            .unwrap_or(0);
+        Ok((unread, server_total))
+    }
+
+    pub fn get_total_unread_count(&self) -> Result<i32, Box<dyn Error + Send + Sync>> {
+        let conn = self.connect()?;
+        let count: i32 = conn.query_row(
+            "SELECT COUNT(*) FROM messages_v2 WHERE is_read = 0 AND LOWER(folder) = 'inbox'",
+            [],
+            |row| row.get(0),
+        )?;
+        Ok(count)
+    }
+}

mailcore/src/types.rs

@@ -0,0 +1,154 @@
+use flutter_rust_bridge::frb;
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MailServerConfig {
+    pub imap_host: String,
+    pub imap_port: u16,
+    pub smtp_host: String,
+    pub smtp_port: u16,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MessageHeader {
+    pub uid: u32,
+    pub subject: String,
+    pub from: String,
+    pub to: Vec<String>,
+    pub date: i64,
+    pub is_read: bool,
+    pub has_attachments: bool,
+    pub pgp_status: PgpStatus,
+    pub flag: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub enum PgpStatus {
+    None,
+    /// Message was encrypted by the sender (requires recipient private key to read).
+    Encrypted,
+    Signed,
+    SignedAndEncrypted,
+    InvalidSignature,
+    /// Message stored at rest encrypted with the user's own public key.
+    EncryptedAtRest,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct MessageBody {
+    pub uid: u32,
+    pub from: Option<String>,
+    pub text_plain: Option<String>,
+    pub text_html: Option<String>,
+    pub attachments: Vec<Attachment>,
+    pub pgp_status: PgpStatus,
+    pub signature_fingerprint: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Attachment {
+    pub name: String,
+    pub content_type: String,
+    pub size: usize,
+    pub content: Vec<u8>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Contact {
+    pub email: String,
+    pub display_name: Option<String>,
+    pub public_key: Option<String>,
+    pub fingerprint: Option<String>,
+    pub trust_level: TrustLevel,
+    pub first_seen: i64,
+    pub last_seen: i64,
+}
+
+#[frb]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub enum TrustLevel {
+    Unknown,
+    Trusted,
+    Established,
+    Warning,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Draft {
+    pub id: Option<i64>,
+    pub to: String,
+    pub subject: String,
+    pub body: String,
+    pub attachments: Vec<Attachment>,
+    pub last_updated: i64,
+    pub last_synced_at: i64,
+    pub server_uid: Option<u32>,
+}
+
+#[derive(Debug, Clone)]
+pub struct PgpKeyPair {
+    pub public_key: String,
+    pub private_key: String,
+    pub key_info: String,
+    pub fingerprint: String,
+    pub user_ids: Vec<String>,
+}
+
+#[frb]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub enum MailError {
+    Generic(String),
+    Network(String),
+    Auth(String),
+    PassphraseRequired,
+    InvalidPassphrase,
+    KeyNotFound(String),
+    Crypto(String),
+}
+
+impl std::fmt::Display for MailError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            MailError::Generic(s) => write!(f, "{}", s),
+            MailError::Network(s) => write!(f, "Network error: {}", s),
+            MailError::Auth(s) => write!(f, "Auth error: {}", s),
+            MailError::PassphraseRequired => write!(f, "Passphrase required"),
+            MailError::InvalidPassphrase => write!(f, "Invalid passphrase"),
+            MailError::KeyNotFound(s) => write!(f, "Key not found: {}", s),
+            MailError::Crypto(s) => write!(f, "Crypto error: {}", s),
+        }
+    }
+}
+
+impl std::error::Error for MailError {}
+
+#[frb]
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
+pub enum FolderType {
+    Inbox,
+    Sent,
+    Drafts,
+    Trash,
+    Junk,
+    Archive,
+    Custom,
+}
+
+#[frb]
+#[derive(Debug, Clone)]
+pub struct FolderStats {
+    pub unread: i32,
+    pub server_total: i32,
+}
+
+#[frb]
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct FolderInfo {
+    pub name: String,
+    /// Raw server-side folder name in IMAP Modified UTF-7 encoding.
+    /// Use this when issuing IMAP SELECT/EXAMINE/APPEND commands.
+    pub imap_name: String,
+    pub folder_type: FolderType,
+    pub is_selectable: bool,
+    pub unread_count: i32,
+}