The killer feature that did it for me was being able to bulk manage/delete email, keep an offline copy and (hence) enable full text search when offline. I was

The killer feature that did it for me was being able to bulk manage/delete email, keep an offline copy and (hence) enable full text search when offline. I was in a situation where I couldn't quite get a grip on all the newsletters and spam that had accumulated, so I paid for a SaaS service to sort mail, delete and highlight for unsubscribing. When I was able to get neomutt set up (with Luke Smith's mutt-wizard scripts), I found it was pretty easy to do these things with just a few button pressed. Since it's a terminal app it feels very responsive, so you get the removal of friction between thought and action that you do with vim. I've tried to do the same with outlook on my work Windows machine and it's not as smooth - I probably wouldn't have bothered if I hadn't got the usage pattern down in neomutt. I use Gmail for a lot of my rules and filtering, but I realise that if I ever wanted to leave Gmail then many of these 'smart' features wouldn't be available in the same way. I would, however, be able to script similar rules in mutt which takes a lot of overhead out of my email/communication/personal organisation. Also neomutt/maildir makes it easy to use your email in scripts. You can use them as triggers or as a data source - they're just available in plain text format. So yes, a lot of advantages, probably most could be emulated in GUIs, but it does sit much more neatly with Unix/terminal ways of working.