I have a problem that started today -- email is piling up in the exchange queue. Some of it will trickle out slowly. If I reboot the server, it will send out all the mail sitting in the queue, but after about 30 minutes or so, it slows down again and the queue starts filling up. My first thought was back pressure and indeed, this morning the C drive was getting a little low (although not below the threshold). It is currently sitting at 15.2GB of free space.
Is there something else that can cause back pressure? We use Trend AV and I disabled the services to see if that was causing it.
We are migrating to Outlook 365 within the next couple days, but people really can't do their jobs when email isn't functioning -- I'd really like to get this fixed.