Why does this occur and error?
[Exchange Web Services] Creating or updating folder ‘/Partners & Software/Epic’ failed due to the following error: ErrorFolderExists
Sounds like there is already a folder there with that name, or a duplicate folder with the same name, or there is a problem with that folder or possible a problem with the account itself.
So first “check if there is already a folder with the same name” in eM Client and also check on the mail server end online via your Webmail gui.
If there isn’t a duplicate folder and only the one folder, then I would suggest to “copy the emails out of that folder into another folder” and then “recreate that same folder” and then move those emails back into that folder again. Then close and reopen eM Client and see if that fixes it when it re-syncs again.
If it still doesn’t fix it and there is definitely no duplicate mail folder with the same name, then I would next try running the repair on your ews mail account to resync it with the server.
Before running the repair “make a manual backup” via “Menu / Backup” in case you need to restore for any reason. You can see when that completed in Show Operations via clicking the dropdown on the right of Refresh top left.
To run the repair “right click on your ews account Inbox” and then click “Properties” at the bottom. Then click the Repair tab along the top and click Repair. The repair clears the local mail cache and resyncs with the server, so messages will be slower to reread till fully cached.
Lastly if after running the repair still has the same problem, then I would next go to “Menu / Accounts” and remove and readd your account.