Email Sent from my Domain for Non-Existent Email Addresses
Question asked by Cliff Hammock - December 21, 2015 at 2:41 PM
I started getting a lot of "delivery delayed" emails like the one below. 
The server(s) that the message "RE:" is attempting to be sent to has temporarily delayed the delivery for the following recipient(s):

There will be up to 12 more delivery attempt(s) of this message. Do not re-send your message until there are no more delivery attempt(s) and the messages bounces back to you.
But it shows the email is from  and this is not a valid email address on my SM installation. The domain is correct, but there isn't an account for that user. I currently only operate my mail server for my own business emails. I looked in my spool and there are hundreds of outgoing emails from addresses that don't exist on my server. I have tried to keep my SM install security updated based on the security settings recommended here, but something must not be right. I ran some diagnostics and it says rDNS is OK and it is not an open relay. 
I don't really have a good idea what the problem might be? But obviously this is a pretty bad thing that I need to resolve quickly. 

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Rod Lasky Replied
Employee Post Marked As Answer
Hi Cliff.  Without viewing your logging details, I can't verify what's happening.   But to help, please check the following:
Also, in Settings >> Protocol Settings >> SMTP In tab, adjust your settings to these:
Allow Relay: Nobody
This will force all relay attempts through your SmarterMail server to authenticate first.
Require Auth Match:  Email Address.
This will require that the authenticated address matches the 'from to' address in the email.
For safe measure, I would bounce the SmarterMail service also.
If you're still experiencing an issue afterwards, please submit a support ticket and we'll look into this for you.
Rod Lasky
Technical Support Specialist
SmarterTools Inc.
(877) 357-6278
Thanks Rod. I had the Relay setup correctly. I changed the Require Auth Match to Email Address and no more problems. I deleted all the items in the SPOOL and no others have shown up. I don't see anything about that particular setting in the ST Online Help system, so I am not sure exactly what it does. But it did solve my problem and I really appreciate your guidance.
Dzung Huynh Replied
"For safe measure, I would bounce the SmarterMail service also."
Where do you actually do this step?
Von-Austin See Replied
Employee Post
Dzung, this is done within the Windows Services console. You can access this by accessing Start -> Run, enter services.msc and hit OK. Then locate the SmarterMail service, and issue a stop. Wait for mailservice.exe to terminate completely before starting it back up.

I hope this helps.
Von See
Technical Support Supervisor
SmarterTools Inc.
(877) 357-6278

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