FORCED to change from POP3 to IMAP

I was having a problem with my Outlook 2016 email not sending out.  I saw other posts about the change in port which didn't work.

Anyway, I was told by Xfinity/Comcast the problem was, i was POP3 and not IMAP and HAD TO make the change. 

Hours later, there was NO change, send error.  NOTE:  The solution I found was to set Encrypt to "Auto" not SSL/TLS... which ended up working on multiple computers (POP3 and my IMAP).

Does anyone know when "besides soon" that POP3 will be totally dumped and IMAP will be the only solution?

I want to change mine back to POP3 if I can.