feat: remove last usage of XDELTAPUSH capability

src/imap.rs

@@ -129,6 +129,8 @@ pub(crate) struct ServerMetadata {
     /// True if we think the relay supports push notifications.
     /// This gates wether we attempt to write an encrypted device token
     /// to per-transport IMAP metadata key `/private/devicetoken`.
+    ///
+    /// Any `/shared/vendor/deltachat/` entry identifies a chatmail relay.
     pub supports_push: bool,
 
     /// ICE servers for WebRTC calls.
@@ -1384,6 +1386,8 @@ impl Session {
                 _ => {}
             }
         }
+        let supports_push =
+            max_smtp_rcpt_to.is_some() || iroh_relay.is_some() || ice_servers.is_some();
         let ice_servers = if let Some(ice_servers) = ice_servers {
             ice_servers
         } else {
@@ -1399,7 +1403,7 @@ impl Session {
                 admin,
                 iroh_relay,
                 max_smtp_rcpt_to,
-                supports_push: max_smtp_rcpt_to.is_some() || self.capabilities.has_xdeltapush,
+                supports_push,
                 ice_servers,
                 ice_servers_expiration_timestamp,
                 app_versions,

src/imap/capabilities.rs

@@ -25,9 +25,6 @@ pub(crate) struct Capabilities {
     /// <https://tools.ietf.org/html/rfc4978>
     pub can_compress: bool,
 
-    /// True if the server advertises the legacy `XDELTAPUSH` capability.
-    pub has_xdeltapush: bool,
-
     /// True if the server has an XCHATMAIL capability
     /// indicating that it is a <https://github.com/deltachat/chatmail> server.
     ///

src/imap/client.rs

@@ -82,7 +82,6 @@ pub(crate) async fn identify_server(
         can_check_quota: caps.has_str("QUOTA"),
         can_metadata: caps.has_str("METADATA"),
         can_compress: caps.has_str("COMPRESS=DEFLATE"),
-        has_xdeltapush: caps.has_str("XDELTAPUSH"),
         is_chatmail: caps.has_str("XCHATMAIL"),
         server_id,
     };