Offer non-proportial/monospaced font (and generally more font configurability)

[sgofferj]

Is your feature request related to a problem? Please describe.

I'm an old-fashioned Linux/Unix guy who is used to read and write mails in monospaced fonts - NC mail doesn't offer any font selection/configuration, neither for reading, nor for writing text/plain mails.

Describe the solution you'd like

Make font for reading/writing mails configurable. At the very least monospaced/proportional. Additional size setting would be helpful too for us Gen X-ers with half a kilo of glass on our noses.

Describe alternatives you've considered

No response

Additional context

No response