Support opt-in UIDONLY acquisition for large Yahoo mailboxes

crates/admin/src/meta.rs

@@ -256,6 +256,7 @@ impl From<AccountV3> for AccountModel {
             updated_at: value.updated_at,
             created_by: value.created_by,
             use_dangerous: value.use_dangerous,
+            uidonly_enabled: false,
             pgp_key: value.pgp_key,
             imap_quota_window: None,
             imap_quota_bytes: None,
@@ -666,6 +667,7 @@ impl From<MailBox> for bichon_core::cache::imap::mailbox::MailBox {
             uid_next: value.uid_next,
             uid_validity: value.uid_validity,
             highest_uid: None,
+            uidonly_source_scope: None,
         }
     }
 }

crates/blob/src/bucket.rs

@@ -163,6 +163,27 @@ impl IndexStore {
         self.get(key).map(|r| r.is_some())
     }
 
+    /// Check several keys in one read transaction.
+    pub fn exists_batch(&self, keys: &[[u8; 32]]) -> Result<Vec<bool>> {
+        let txn = self
+            .db
+            .begin_read()
+            .map_err(|e| crate::error::Error::IndexDb(format!("read txn: {}", e)))?;
+        let table = txn
+            .open_table(INDEX_TABLE)
+            .map_err(|e| crate::error::Error::IndexDb(format!("open table: {}", e)))?;
+        keys.iter()
+            .map(|key| {
+                let record = table
+                    .get(key)
+                    .map_err(|e| crate::error::Error::IndexDb(format!("get: {}", e)))?
+                    .map(|guard| IndexRecord::decode(&guard.value().0))
+                    .transpose()?;
+                Ok(record.is_some_and(|record| !record.is_tombstone()))
+            })
+            .collect()
+    }
+
     /// Insert or update a record for a key.  Committed in a single write txn.
     pub fn insert(&self, record: &IndexRecord) -> Result<()> {
         let txn = self

crates/blob/src/engine.rs

@@ -320,6 +320,10 @@ impl Engine {
         self.shared.index_store.exists(key)
     }
 
+    pub fn exists_batch(&self, keys: &[[u8; 32]]) -> Result<Vec<bool>> {
+        self.shared.index_store.exists_batch(keys)
+    }
+
     // ── Batch delete ─────────────────────────────────────────────────────
 
     pub fn delete_batch(&self, keys: &[[u8; 32]]) -> Result<()> {
@@ -375,7 +379,6 @@ impl Engine {
 
         let mut records: Vec<IndexRecord> = Vec::with_capacity(entries.len());
         let mut ends: Vec<(u32, u64)> = Vec::with_capacity(entries.len());
-
         for (key, value, codec) in entries {
             if value.len() > crate::types::MAX_VALUE_SIZE {
                 return Err(Error::ValueTooLarge { size: value.len() });

crates/core/src/account/migration.rs

@@ -39,7 +39,7 @@ use crate::{
     id,
     oauth2::token::OAuth2AccessToken,
     raise_error,
-    store::tantivy::{attachment::ATTACHMENT_MANAGER, envelope::ENVELOPE_MANAGER},
+    store::tantivy::envelope::ENVELOPE_MANAGER,
     users::{payload::UserUpdateRequest, role::DEFAULT_ACCOUNT_MANAGER_ROLE_ID, UserModel},
     utc_now,
 };
@@ -301,6 +301,9 @@ pub struct Account {
     pub updated_at: i64,
     pub created_by: u64, //user id
     pub use_dangerous: bool,
+    /// UIDONLY acquisition is opt-in because it changes remote message identity.
+    #[serde(default)]
+    pub uidonly_enabled: bool,
     pub pgp_key: Option<String>,
     pub imap_quota_bytes: Option<u64>,
     pub imap_quota_window: Option<QuotaWindow>,
@@ -345,6 +348,7 @@ impl Account {
             created_at: utc_now!(),
             updated_at: utc_now!(),
             use_dangerous: request.use_dangerous,
+            uidonly_enabled: request.uidonly_enabled.unwrap_or_default(),
             pgp_key: request.pgp_key,
             created_by: user_id,
             download_batch_size: request.download_batch_size,
@@ -502,9 +506,6 @@ impl Account {
         ENVELOPE_MANAGER
             .delete_account_envelopes(account.id)
             .await?;
-        ATTACHMENT_MANAGER
-            .delete_account_attachments(account.id)
-            .await?;
         Self::delete_account(account)?;
         info!("Sequential cleanup completed for account: {}", account.id);
         Ok(())
@@ -671,6 +672,10 @@ impl Account {
             new.use_dangerous = use_dangerous;
         }
 
+        if let Some(uidonly_enabled) = request.uidonly_enabled {
+            new.uidonly_enabled = uidonly_enabled;
+        }
+
         if let Some(pgp_key) = request.pgp_key {
             new.pgp_key = Some(pgp_key);
         }
@@ -707,6 +712,32 @@ impl Account {
 mod tests {
     use super::*;
 
+    #[test]
+    fn uidonly_setting_defaults_off_and_only_changes_explicitly() {
+        let account = Account::new(1, AccountCreateRequest::default()).unwrap();
+        assert!(!account.uidonly_enabled);
+        let update = |old: &Account, value| {
+            Account::apply_update_fields(
+                old,
+                AccountUpdateRequest {
+                    uidonly_enabled: value,
+                    ..Default::default()
+                },
+            )
+            .unwrap()
+        };
+        let enabled = update(&account, Some(true));
+        assert!(enabled.uidonly_enabled);
+        assert!(update(&enabled, None).uidonly_enabled);
+        assert!(!update(&enabled, Some(false)).uidonly_enabled);
+
+        let mut legacy = serde_json::to_value(enabled).unwrap();
+        legacy.as_object_mut().unwrap().remove("uidonly_enabled");
+        assert!(!serde_json::from_value::<Account>(legacy)
+            .unwrap()
+            .uidonly_enabled);
+    }
+
     // ── FilterRule ───────────────────────────────────────────────────
 
     #[test]

crates/core/src/account/payload.rs

@@ -52,6 +52,9 @@ pub struct AccountCreateRequest {
     pub download_batch_size: Option<u32>,
     pub max_email_size_bytes: Option<u64>,
     pub use_dangerous: bool,
+    /// Explicitly enables UIDONLY acquisition when required by the server.
+    /// Omitted values remain disabled for backward compatibility.
+    pub uidonly_enabled: Option<bool>,
     pub pgp_key: Option<String>,
     pub imap_quota_bytes: Option<u64>,
     pub imap_quota_window: Option<QuotaWindow>,
@@ -188,6 +191,8 @@ pub struct AccountUpdateRequest {
     pub download_batch_size: Option<u32>,
     pub max_email_size_bytes: Option<u64>,
     pub use_dangerous: Option<bool>,
+    /// Enables or disables UIDONLY acquisition for this account.
+    pub uidonly_enabled: Option<bool>,
 
     pub pgp_key: Option<String>,
     pub imap_quota_bytes: Option<u64>,

crates/core/src/account/view.rs

@@ -52,6 +52,7 @@ pub struct AccountResp {
     pub created_user_name: String,
     pub created_user_email: String,
     pub use_dangerous: bool,
+    pub uidonly_enabled: bool,
     pub pgp_key: Option<String>,
     pub imap_quota_bytes: Option<u64>,
     pub imap_quota_window: Option<QuotaWindow>,
@@ -90,6 +91,7 @@ impl AccountResp {
                 .map(|u| u.email.clone())
                 .unwrap_or_else(|| "N/A".to_string()),
             use_dangerous: account.use_dangerous,
+            uidonly_enabled: account.uidonly_enabled,
             pgp_key: account.pgp_key,
             imap_quota_bytes: account.imap_quota_bytes,
             imap_quota_window: account.imap_quota_window,