Email won't stay deleted (IMAP) Phone: Samsung Galaxy S4
App: default mail app (Android or Samsung, don't know which)
Issue: I have an IMAP email account and when I delete an email and then check for new messages later, or at the scheduled sync frequency, those emails reappear in the account - they won't stay deleted.

I can't use K-9 mail as it doesn't support Exchange Server and I have an Exchange account as well. The problem account is set up as IMAIL. I don't see any options anywhere to change server settings for deleting emails on the server as well. Any ideas?
In my opinion there is an issue with the default mail app on the Samsung Galaxy phones.
I have recently switched from iPhone to Galaxy Note 3 and was really disappointed with the mail app not properly deleting emails from the server using imap. I know what I am doing and have it successfully working on other DROID and ios devices.
My work - around is to not use the trash can icon to delete mail but instead to use the move icon and choose to move the mail to the INBOX.trash folder.
Or you could just use Maildroid as there is much more control over what you want to do. 
I am back on the default mail app now and happy with my work - around as the samsung email app works best with the Galaxy Gear smart watch.