Hello,
I have a single server setup for Exchange 2013 and recently had an issue with Maintenance mode during updates. I was in the process of getting the server upgraded to SP1 when it happened. I had tried to run the service pack when it returned an error saying something was pending and it couldn't install. Because the server had several windows updates and 1 Exchange 2013 security update downloaded from wsus, I thought it was obviously this. So I cancelled out of the sp1 install and ran the updates. Once the updates were finished and the server rebooted, mail wouldn't flow. Found out it was because it was in Maintenance mode.
I'm not sure if it was the SP1 install or the security update that placed the server in this mode, but it seemed like it was the security update(KB2880833.) From what I've found on the interwebs, Maintenance mode is meant for High Availability setups, which mine is not and it has to be put into that mode mannually. I never put the server into this mode. Is this done automatically by running updates or Service packs? and if so, how can I turn prevent it from happening automatically? Is it necessary? I have no reason to use it, as we only have one server. I've found plenty of info on how to turn it on or off, but nothing about any automatic settings.
THanks for any guidance.