[CTOSian]

There is `Mutt` console email, linux mainly , on windows under cygwin, alas does not deal well with HTML emails, it can be connected to Gmail anyway.

[layer8]

Reading HTML email is fine under mutt with w3m. What's difficult is replying to HTML emails without losing the HTML for the quoted message.

[ericpruitt]

I use Mutt almost exclusively, but I still use the Gmail web interface to write emails from time to time for this very reason. If you want to send emails verbatim, you can use Mutt's bounce feature, but that can confuse the recipient since bouncing leaves the original headers in-tact, including the "Date" header which means the email might not appear at the top of the user's inbox.

[layer8]

Bouncing also doesn’t work with strict DKIM/DMARC verification if the sending domain differs.