FEAT: Add plaintext mode

[mdosch]

Is your feature request related to a problem?

I prefer to write plaintext mails and I find it a bit strange that matcha sends multipart mails with text and html part although I wrote a plain text mail.

Describe the solution you'd like

Maybe it would be nice to have a setting for sending plaintext only for nerds like me. This should also set format=flowed. You can find advice for plaintext mode here.

Describe alternatives you've considered

No response

Additional context

No response

[andrinoff]

Thank you for the issue!

The problem is that it runs through markdownToHTML() and it will always build a multipart.

Just wondering though, why is that an issue for you?

[mdosch]

Dear Drew, thank you for the fast reply. It is not really an issue for me, but as a plaintext proponent I find it a bit strange to send a multipart mail containing a html part which is identical to the plaintext part. :)