We recently upgraded from Exchange 2003 to Exchange 2007. I have a user that receives the following message when she sends to distribution lists.
firstname.lastname@example.org (user name with held)
A communication failure occurred during the delivery of this message. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message later, or provide the following diagnostic text to your system administrator.
She receives this message for each external email address in the distribution list, but does not receive it for any of the internal email addresses. When she calls the people to ask them to check with their email admins, they tell her that they did receive the email.
The delivery failure message only appears when she uses a distribution list, and it only shows external email addresses as having errors. If she sends an email to an indvidual from the list she does not receive any error messages.
We have had her delete and re-create her distribution lists, but she still has the same problem. She is the only one of +2500 users on the network to report the problem.
Any assistance is greatly appreciated.
Thanks in advance,
Please first test this issue in OWA, and let me know the result.
Then improve the diagnostic level on the phase of store and transport to get the more information in order to better diagnose this issue.