Hi,I have an Exchange 2003 server which has started experiencing significant latency (lag) in message delivery in the past 2-4 weeks. Some users (not all) are reporting that messages are taking many minutes, sometimes 20 minutes to an hour to arrive. This is true for internal email (sender and recipient both on this Exchanges erver) or external email (emails from outside being delivered to Exchange user, or Exchange user sending to an external user).I have defragged the store, and also tried moving mailboxes to another store. I have checked event logs for any clues but don't see anything that would imply an issue. The queue is typically very small, 50 to 100 messages, all small in size and mostly to non-deliverable external addresses which does not sound like it should be holding up everyone else. The server typically processes 10000 to 20000 emails per day so a queue of 90 should probably be OK. RAM usage is less than 50% of physical memory (4GB real, about 1.7GB typically used, store.exe is using maybe 800MB to 1.2GB). No disk errors or issues in the event log. The server CPU is a Xeon 3GHz and CPU utiliztion is always quite low, around 10-15%.This behavior is relatively recent, perhaps in the last 2-4 weeks. Server traffic has not changed noticeably during that period, i.e. SMTP log files are about the same size they have always been, bandwidth usage is about the same over the past 6 months etc. Also, not all users are reporting the issue, but there is no obvious pattern to them ( e.g. all on one store, or one OU in the AD etc.).I did notice that when I was moving mailboxes from one store to another, it was slow as molasses. It took 3 hours to move 10 mailboxes, none of which were "huge" (maybe 50MB to 300MB in size). That seems odd, I would have expected the mailbox move (in ESM) to whizz by at amazing speeds especially on a Sunday morning.Any suggestions as to what I should look at to analyze where the latency in delivery is? Are there any tools (apart from "Windows Performance Monitor" which I ran but did not show any obvious issues)? Are there any tuning suggestions for Exchange message delivery?Any help would be appreciated! (other than "google is your friend" or "go buy some books" thanks LOL).best regardsJ. W.