Hello, just taking over admin of the Ipswitch mail system here at my company. Is there anything that would cause a single (known good) email domain to consistently bounce back? The owner has one biz partner he needs to email with, can email from his AOL or my Yahoo account, but when mailing from our company domain under iMail it always bounces back. I don't see anything in the admin controls that would cause this, although I remember awhile back my predecessor had some issue with emails to hotmail.com bouncing back. Any advice on what's up?

Thank you,

Scott Huff/Chicago

Scott,

There could be several reasons why the remote mail server could be rejecting the messages sent from your mail server.  Could you post the return message that you are receiving when you attempt to send email to that domain?

I suspect that the problem is that the messages that you are sending to the remote mail server is failing some sort validation that the remote mail server is using.  These validations can range from validating that the IP of the sending mail server (making sure it's not a residential IP, or on a blocked list of IPs), DNS black lists, open relay black lists, verification of EHLO/HELO domain, etc.

The best way to start is to enable verbose logging for the SMTP service (Imail Administrator -> Services -> SMTP).  I'm still running Imail 8.03 so this might be a bit different.  You will then be able to view the transaction between your mail server and the remote mail server in your syslog.  Send an email to the domain that is giving you trouble and look in the syslog.  That should probably give us an indication of what is going on.  Post the section from your log if you have any other questions.

Nick