I switched back to mutt 5 months ago, when my startup started to grow fast and I needed a sensible way to deal with lots of email in multiple accounts. I haven't looked back. I still have gmail as a back-end, but I use mbsync to keep local copies of all my accounts, and msmtp to send mail.

Some resources I found helpful:

- http://stevelosh.com/blog/2012/10/the-homely-mutt/ (good, but it recommends offlineimap — I tried it and found it to be slow and buggy. mbsync is much better.)

- https://github.com/cbracken/mutt

- https://lukespear.co.uk/mutt-multiple-accounts-mbsync-notmuc...