Here's the basic scenario:We recently migrated from E2003 on an older server to E2007 on a brand new server. Neither is a domain controller. The whole migration went fairly hastily due to a sudden hardware issue with the 2003 server. Currently, all mailboxes and a handful of public folders are on 2007. A smattering of public folders are still physically on 2003, replicated to 2007.Every morning, an email is sent to a particular mail-enabled security group. It usually takes 15-30 minutes for this email to be delivered. The behavior is the same regardless of the sender. The group was created in 2003 and migrated over; it used to be a global group, but I've converted it to a universal group. I want to say this was happening before migration, but I can't find any evidence of a complaint at that time. Membership currently is 3 other mail-enabled universal security groups and one email contact pointing to an external SMTP address. If I remove all members and just add myself, the messages come through immediately, which means the issue is with group membership. However, the organization will not allow me to send test messages to such a widespread number of recipients for testing purposes. So: does anything jump out as being the obvious fly in the ointment? I keep coming back to that email contact as the culprit, but as it's an important person, I'm not allowed to remove it, even for testing. Thanks for any insight!

What expansion server does the group currently have? Can you set this to be the Exchange 2007 server only and test again?

This particular group had only the 2007 server as expansion server, but two of the member groups were set to any server. I've changed all over to the 2007 server; we'll see tomorrow AM if that helps. Thanks!

I'd say, you should track the message in pipelining process and see at which stage is this delayed. At maximum use ExTRA tracing to find out more.

I will have to try your suggestion, as changing the expansion server did not change things.