Today I set myself the goal of centralizing all my email. Before I finished this change I had 50/50 POP email that was delivered to my home computer, and the other mail is sitting on an IMAP server.

For years (since 2006) I have had email stored between different POP clients, from Micro$oft Outlook Express, to their non-Windows XP Microsoft Mail client, and then finally importing it all to Thunderbird. After performing some experiments I comfortably learned that I can take a file stored in Thunderbird and have Dovecot read it perfectly with no issues.