Members of certain OUs periodically bouncing from Distribution List emails
Posted on 2006-11-28
First off, I'm running a Windows 2003 Server with Exchange 2003 (Both latest SP and fully patched) in a two tier domain (parent and child domains) and I'm having an intermittent problem where members of certain organisational units in the AD have emails sent to them via distribution lists bounce (but direct send to that user does work correctly). Interestingly the bounce always indicates it tried to send to the name as you would navigate to it via ADSI or AD (there's a term for that but I can't think of it).
The following recipient(s) could not be reached:
CN=<name removed>,OU=Call Centre,OU=Users,OU=Department,DC=dpt,DC=dialectgroup,DC=internal on 29/11/2006 2:24 PM
The message could not be delivered because the recipient's destination email system is unknown or invalid. Please check the address and try again, or contact your system administrator to verify connectivity to the email system of the recipient.
An email that does this will bounce to all other members of that particular OU (sometimes several OUs) but distribute fine to many other OUs, and will continue bouncing until I delete the sender's outlook address book and rebuild after which it will send fine for a few weeks then the problem resurfaces (often on a different users PC).
Interestingly when I look at the distribution list via AD Users and Computers after being told of one of these bounces, the members in question appear slightly greyed out in the list but nothing has changed about their account or the list itself, in fact after the most recent one the system had been static for nearly three weeks with only monitoring tasks having happened.
This one has got me really stumped, so if anybody can point me in the direction of what i can do to diagnose cause, or better yet if somebody else has encountered and solved, I'd really appreciate it.