Often the underlying cause of this problem can be rectified by following one of the points below:
1. Check that the toolbar isn’t disabled at File -> Options -> Add-ins -> Manage : Disabled Add-ins.
If Outlook crashes it may prompt you to start in safe mode the next time you open it. If you do so, Outlook disables all it’s non-Microsoft plugins. However, this remains the case even when you re-open Outlook in “normal” mode.
2. Check that the toolbar isn’t hidden. Right click in the toolbar location at the top of Outlook choose “Customise the Ribbon”. Ensure MDaemon Connector is still ticked in this location.
3. Check that MDaemon Connector is still present and ticked in File -> Options -> Add-ins. If it is not present, re-run the MDaemon Connector client installer.
4. Check there isn’t more than one copy of Outlook.exe running in Task Manager -> Details.
If the above points don’t resolve the issue, we’d suggest creating a fresh uniquely name mail profile via the Mail icon in the Windows Control Panel. When you open Outlook in this profile, this will cause MDaemon Connector to pull in all the mailbox data from the MDaemon server again.