Route limited mailboxes through opt-in UIDONLY acquisition

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/core/src/account/migration.rs

@@ -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,
@@ -668,6 +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);
         }
@@ -704,6 +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,