Hi,I have a customer reported the following issue where internal emails were delayed up to an hour. Any help would be appreciated. Their current infra is as follows:Single site - 3 DCs with GC on W2K81 x SCC MB - E2K7 SP2 on W2K83 x CASHUB - E2K7SP2 on W2K8All servers runs OfficeScan AV and ForeFront for Exchange were installed on all E2K7.Eventlogs does not show any symptoms.

Is this happening to some users (on any particular VLAN or OU or any particular Exchange Store)?Also check how is external mails coming in? Are they on time or getting delayed? Check also the sender's outbox , if that getting stuck there for some time?Check on message tracking. See where its getting delayed. I am almost sure it will be on categorizer. shut down the AV's on Exchange (just for testing) and see if that makes any difference.Raj

This only affect certain users. It also happens when user send a mail to an internal DL.External mails looks ok. Message tracking does not show any signs. It reported mail submited xx:xx and delivered xx:xx. When others received the mail the interval is about an hour delay.I'm getting them to shutdown the AV and monitor.

If this is only happening to DL, Is this happening to only some members of the DL or all of them??Send individual emails to the problematic users and see if that goes on time?Raj