Assuming it's the auth stuff with 365 and the inability to create long-term app passwords; DavMail might solve the problem: https://sourceforge.net/projects/davmail/
It can handle the Office365 stuff (including Oauth2) and basically translates MS "junk" into standard protocols (POP, IMAP, CalDAV, CardDAV, etc). So if you got that to work, you could point getmail at davmail's imap port, and continue to use it like normal.
It can handle the Office365 stuff (including Oauth2) and basically translates MS "junk" into standard protocols (POP, IMAP, CalDAV, CardDAV, etc). So if you got that to work, you could point getmail at davmail's imap port, and continue to use it like normal.