A couple of things that are missing from pretty much any popular email client is
The following sections explore these in a little more detail.
One thing that most email clients lack is more advanced configurability, particularly to shortcuts. Thunderbird, for example, defaults to having
j move an email to the junk folder, and there's no simple way of reconfiguring it. If you know Vim, then you understand that
j is used to move down by one line.
Fortunately, command-line applications tend to have a huge benefit in terms of configurability.
It is entirely possible that you may feel that there is no need to have any additional actions or scripting for emails. Modern clients help reply, and even, for example, may offer options to automatically reply with short messages.
The problem is that these actions are limited. Plugins may extend this a little, but are frequently pushed out of date by a client that has other priorities than supporting whatever specialised requirement you may have.
Let's have a look at a couple of specific examples to see if you may find more specialised tasks useful.
Perhaps you would like PDFs sent from a specific email to be automatically put into an "invoices" folder, and organised in sub-folders by month and year. Or perhaps you might like to add any email you send yourself with a subject starting with "TO DO" to a personal to-do list. Anything is possible when it comes to the command line, and a standard format for storing emails, called MailDir. MailDir is really simple to work with as each email is in its own file.
Of course this is highly subjective, but if you already use Linux, and are willing to put in a little extra time in learning a command-line email client such as Mutt or AERC, then I believe you won't even look back.
I have used Mutt for a few years now, and every aspect of it is configurable - actually the configurability is both a positive and a negative, as Mutt configurations can become quite complicated, and it will take a while to get a set-up specifically to your liking.
However, you can add icons to emails, have shortcuts to specific and custom tasks, it handles multiple accounts with ease, and when you finally have a good configuration it is amazing to use.
For a long time, I thought it would be the only email client I would use for my home accounts. Until recently.
AERC is a relative newcomer, written in Go, and was originally written specifically to handle emails around open source Git repositories. However, it is an extremely fast and efficient email client. It's still in beta, but is undergoing regular work. One feature currently being worked on is the feature I've been anticipating for the last year is theming, and hopefully in the next week or two that will be in place.
Part of its speed comes from its focus; it doesn't try to do everything (that Mutt does), but what it does it does well.
It hasn't quite supplanted Mutt completely for me, as there are a couple of things missing: theming, and managing contacts isn't quite working right for me, although it does theoretically support
abook and auto-completion of contacts. However, even with these short-comings, I rarely use Mutt any more.
Finally, there are a couple of misconceptions about text-mode email clients (such as AERC or Mutt) that I would like to address:
cto compose a new message, tab-complete a contact to send to, and compose, save and press
yto send. Mutt even shows you what keys to press!