Hi Kevin, before trying anything new it’s always wise to make a backup first. (it’s on Menu/File/Backup).
You could try creating a separate account using POP3 and see if it does what you want it to.
I’m in no position to guarantee the results though, so it might be worth bouncing the idea off your contact at eM Client (Anthony Cooper).
Good luck!
Just be aware that POP3 does not sync with the server. It will only download new messages in the Inbox, and will not download or sync messages in other IMAP folders including the Sent folder. If you are accessing your email on more than one device, POP3 is not a good solution.
If you want to go the route of changing from IMAP to POP3, you need to first setup the POP3 account in eM Client, then move any messages from the IMAP folders to the newly created POP3 folders. You will end up with some duplicates in the Inbox, so just run eM Client’s Deduplicator on the POP3 Inbox after you have moved everything.
Once you have all the messages and folders moved, you can remove the IMAP account from eM Client. As Peter wisely suggested, make a backup before you do anything.
POP3 won’t have the issue with the plus.net Sent folder. That is only because POP3 does not access the Sent folder on the sever.