fix: advertise extended capabilities pre-auth (matches Gmail/Yahoo/Outlook behavior) (#943)

* fix: advertise extended capabilities pre-auth (matches Gmail/Yahoo/Outlook behavior)

* fix: fixed protocol test to support both (at least for documentation purposes), mirror XAPPLEPUSHSERVICE being first capability advertised by Apple

* fix: remove protocols not supported

Author: titanism

imap-core/lib/imap-tools.js

@@ -739,6 +739,20 @@ module.exports.sendCapabilityResponse = connection => {
         capabilities.push('QUOTA');
         capabilities.push('XLIST');
         capabilities.push('CHILDREN');
+
+        // Advertise extended capabilities pre-auth (matches Gmail/Yahoo/Outlook behavior)
+        capabilities.push('SPECIAL-USE');
+        capabilities.push('UIDPLUS');
+        capabilities.push('CONDSTORE');
+        capabilities.push('UTF8=ACCEPT');
+
+        capabilities.push('MOVE');
+
+        if (connection._server.options.maxMessage) {
+            capabilities.push('APPENDLIMIT=' + connection._server.options.maxMessage);
+        }
+
+
     } else {
         capabilities.push('ID');
         capabilities.push('UNSELECT');
@@ -764,14 +778,12 @@ module.exports.sendCapabilityResponse = connection => {
             capabilities.push('APPENDLIMIT=' + connection._server.options.maxMessage);
         }
 
-        if (connection._server.options.aps?.enabled) {
-            capabilities.push('XAPPLEPUSHSERVICE');
-        }
     }
 
     capabilities.sort((a, b) => a.localeCompare(b));
 
-    connection.send('* CAPABILITY ' + ['IMAP4rev1'].concat(capabilities).join(' '));
+    let protocolCaps = connection._server.options.aps?.enabled ? ['XAPPLEPUSHSERVICE', 'IMAP4rev1'] : ['IMAP4rev1'];
+    connection.send('* CAPABILITY ' + protocolCaps.concat(capabilities).join(' '));
 };
 
 module.exports.validateInternalDate = internaldate => {

imap-core/test/protocol-test.js

@@ -57,8 +57,9 @@ describe('IMAP Protocol integration tests', function () {
                     port
                 },
                 function (resp) {
-                    expect(/^\* CAPABILITY IMAP4rev1 /m.test(resp.toString())).to.be.true;
-                    expect(/^T1 OK/m.test(resp.toString())).to.be.true;
+                    // CAPABILITY should contain IMAP4rev1 (may be preceded by XAPPLEPUSHSERVICE)
+                    expect(/^\* CAPABILITY .*(XAPPLEPUSHSERVICE )?IMAP4rev1 /m.test(resp.toString())).to.be.true;
+                    expect(/^T1 OK /m.test(resp.toString())).to.be.true;
                     done();
                 }
             );