*See UPDATED & UPDATED AGAIN to jump to the issue at hand.
Just discovered that my mail app(s) are not displaying all of my messages in my SENT box(S) and maybe other boxes.
For example when using Mac Mail "Account Info" shows that one of the "Sent" boxes is only 97 KB and contains only 8 Messages but on the server the "Sent" box is 179M and I know contains a lot more than 8 Messages.
Running Dovecot 2.2.33.2 on Ubuntu 18
Any assistance would be appreciated.
UPDATED: I sent a test message from the account and verified that it DID show up in the SENT folder in the mail app and then checked a different mail app on a smart phone and it also showed up in the sent folder.
I then logged into the server to analyze the Sent file. The Sent file DID NOT contain the Sent email and the date/time stamp had not been updated.
Where oh where is Dovecot now saving the Sent email.
UPDATED AGAIN:
Did a little more digging around and apparently during an update Dovecot decided to switch from (Mail) to (Maildir).
Now my question is how do I, easily, move my pre-switch (Mail) "Sent" and other files into the (Maildir) format?
Was reading a little on merging but it does not look to be for the faint of heart.
Would like to be able to do this on individual mailbox files one at a time if possible.
For example I would be fine with moving (Mail) "Sent" to (Maildir) "Sent Old"
I have other (Mail) folders who's content does not seem to have made the transition to (Maildir) that I would also like to migrate.