fix(mail): align queue, outbound hostname, and DKIM selector behavior across the mail server APIs

ts/mail/index.ts

@@ -1,4 +1,5 @@
 // Export all mail modules for simplified imports
+export * from './interfaces.storage.js';
 export * from './routing/index.js';
 export * from './security/index.js';
 
@@ -14,4 +15,4 @@ import { Email } from './core/classes.email.js';
 // Re-export commonly used classes
 export {
   Email,
-};
+};