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

ts/mail/delivery/classes.delivery.queue.ts

@@ -18,7 +18,7 @@ export interface IQueueItem {
   id: string;
   processingMode: EmailProcessingMode;
   processingResult: any;
-  route: IEmailRoute;
+  route?: IEmailRoute;
   status: QueueItemStatus;
   attempts: number;
   nextAttempt: Date;
@@ -237,7 +237,7 @@ export class UnifiedDeliveryQueue extends EventEmitter {
    * @param mode Processing mode
    * @param route Email route
    */
-  public async enqueue(processingResult: any, mode: EmailProcessingMode, route: IEmailRoute): Promise<string> {
+  public async enqueue(processingResult: any, mode: EmailProcessingMode, route?: IEmailRoute): Promise<string> {
     // Check if queue is full
     if (this.queue.size >= this.options.maxQueueSize) {
       throw new Error('Queue is full');
@@ -284,6 +284,10 @@ export class UnifiedDeliveryQueue extends EventEmitter {
   public getItem(id: string): IQueueItem | undefined {
     return this.queue.get(id);
   }
+
+  public listItems(): IQueueItem[] {
+    return Array.from(this.queue.values()).map((item) => ({ ...item }));
+  }
   
   /**
    * Mark an item as being processed
@@ -657,4 +661,4 @@ export class UnifiedDeliveryQueue extends EventEmitter {
     this.emit('shutdown');
     logger.log('info', 'UnifiedDeliveryQueue shut down successfully');
   }
-}
+}