Emacs was one of my first email clients. It was great when email was largely plain text, and IMAP was still rare. Both MH and Gnus were fantastic. HTML email killed Emacs as a mail client for me.
In my experience, the mails that refuse to display anything but "please view this message in your browser" are never mails I actually want to look at.
I'm not arguing that you have to be willing to put up with some friction! But to me it's not that bad.
[edit: typo]
I love being able to write my own Elisp code to have VM work exactly the way I want it.
Viewing html email in emacs is usually pretty easy. The html2text is usually good enough.
The real problem is sending email. Plain text email looks like trash in any modern mail reader. Any recipient will wonder why your email is broken. On a desktop client the lines will be way too short. On a phone, too long.
Format flowed or whatever doesn't solve it. The lines just need to be html paragraphs.
I saw a blog post about an mu4e plugin that would allow you to write your email in markdown, and it will htmlify it for you. That would be a big help, assuming you can preview before sending. It is easy to make markdown errors without a preview.
I disagree on "too short" lines being a problem for desktop, but in any case, it is quite possible to send plaintext mail without 70-column line breaks. How I do so in VM in Emacs: https://lists.nongnu.org/archive/html/viewmail-info/2020-05/...
I've had to stop 25 years of muscle memory of M-q while writing a message, but otherwise the solution seems quite satisfactory.
Perhaps this?
https://www.reddit.com/r/emacs/comments/g6ujzs/sending_richt...
Would be wonderful if this was incorporated into mu4e.
As for html2text, there's also the Python-based html2markdown, which I prefer.
mu4e-html2text-command "html2markdown | grep -v ' _place_holder;'"
1. Receiving html emails in emacs
2. Sending plain-text emails in emacs
I personally do not find 1. to be a problem at all. If the html gets garbled in my automatic html2text conversion (I use html2markdown) then opening it up in Firefox is just a keypress away. Easy.
I agree that 2. is an issue, however in the rare occasions that I do need to write an html email, I just open up Outlook or Gmail or whatever. We don't have to be Richard Stallman about this. You can use another client when you need to. For me, 99% of the time emacs/mu4e is absolutely adequate, and better than the Outlooks/Gmails for a host of reasons. Let's not throw the baby out with the bathwater.
But if you are in a, say consultant role, where quicker email responses to clients, html support, MS Word like highlighting, then this is not it.
I know, for some folks not already familiar with emacs that can sound crazy, but I've already invested in the learning curve.
But more recently, I'm pretty addicted to using the AI suggestions that GMail gives when composing an email.