First, scream. Then check the logs. While the error messages you MIGHT get in an email client are short, they're not very detailed. Check the logs here: C:\Program Files\SWsoft\Plesk\Mail Servers\Mail Enable\Logging\ Ideally, you want to look for the "debug" log for the specific service that isn't working, and near the end of it - assuming that you're having problems NOW. For example, if you open "POP\POP-Debug-yymmdd.log" and scroll to the end to see "Error creating lock file for postoffice example.com mailbox firstname.lastname@example.org. Error (3)" - chances are you've got permissions or update issues. You MAY be able to fix the permissions issues by giving the following perms: MailEnable\postoffices - IME_ADMIN - full control MailEnable\Config\ - IME_ADMIN - full control MailEnable\logging - IME_ADMIN - full control MailEnable\Queues - IME_ADMIN - full control MailEnable\BIN - IME_ADMIN - read & execute But realistically, it's probably a problem on Plesk's end, right? So if the above doesn't help - ESPECIALLY IF YOU CAN STILL SEND EMAIL BUT CANNOT RECEIVE IT, check that the path to your postoffices wasn't hosed by a recent "fix" from Plesk. To do this, open the "Plesk Reconfigurator" and select the option to change the mail data location. If you've already changed it before, chances are good that Plesk moved it around on you again. So move it back. You SHOULD get a warning that the target isn't empty and it's dangerous. Yep. If you're concerned, back it up first. In MY experience (unfortunately, I've got a lot of it for this particular problem) nothing will be overwritten or destroyed, unless you've got two different mail messages for the same user in that very small window of time that the mail was broken. This is extremely unlikely thanks to the GUID msg naming conventions. This is the THIRD TIME in ONE MONTH that I've had to "reconfig" the mail data path back to where it belongs. The first time was when I installed 8.2. The second time was when I installed 8.3. The third time was when I installed 126.96.36.199. This isn't the best of track records. If all else fails, uninstall and reinstall MailEnable again, then reconfig to the correct path AGAIN. Good luck folks.