I personally use (al)pine and I could not agree more.
But here is a different, and I hope very provocative, reason that you should consider a terminal email client:
Local mail delivery does not traverse the Internet, or any network.
So, for instance, when I send an email to one of my engineers at rsync.net, even though it is sent in plaintext, it is a private communication and cannot be intercepted by either an ISP or some global observer. It's nothing but a local file operation between two mailspools...
Further, it would be extremely difficult to phish someone who is viewing their email in the terminal. The effort that it takes to view and copy a URL is greater than the discernment required to identify it as suspicious - so you'll catch them every time.