As of yesterday we had one user complaining that they were getting email kickbacks when sending or replying to a specific domain. Today, I have at least 2-3 more that have issue with the same domain and now others.
IF we send or reply to an email using OWA (instead of the locally installed client), the emails go thru to the recepient.
I have tried deleting the NK2 file, but that didn't resolve the issue.
Some Outlook client installs can email to this domain, but some can't, unless they logon to OWA.
The kickback (NDR) is pasted below.
Any advice is greatly appreciated.
Your message did not reach some or all of the intended recipients.
Subject: testing emails from SBSI
Sent: 01/05/2012 11:40 AM
The following recipient(s) cannot be reached:
'firstname.lastname@example.org' on 01/05/2012 11:40 AM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<server.mydomain.COM #5.5.0 smtp;554 Denied [952d50f4.0.1113496.00-2356.1542179.p01c12m075.mxlogic.net] (Mode: normal)>