internet mail smtp connector queues

When I click on the Queues node in ESM, in the right-hand pane I see tens of
listings which read: "Internet Mail (SMTP) Connector (<server_name>) - <some strange websites> (SMTP Connector)"
The in the Message Tracking Center I see hundreds of Delivery Status Notification (Failure) messages.
So I assume that this is spam: all those websites are trying to send me messages that are not delivered, so my postmaster is notifying them of NDR.
How can I stop them from even hitting my server?
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Engineer_JOConnect With a Mentor Commented:
I think that you have to Filter Out Mail to Non-Existent Users. I faced the same problem and I solved it using the following link:

I hope you to solve your problem

you probably have open relay on ur Exchange server, please close the relay make sure then it's closed and the clean the queues.
How to block open SMTP relaying and clean up Exchange Server SMTP queues

How to help secure the Internet Mail Service and clean up after unsolicited commercial e-mail or spam abuse

If it is all postmaster@ then it is NDR spam, which will be cleared by using he link above to my web site.
If you want to clear the queues, then see my spam cleanup article:

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