[Users] Sending email from plus- or sub-address of Gmail

[Enan Ajmain]

GMail allows plus- or sub-addressing[1]. I can use it properly when
getting an email, i.e., getting an email with `To' header having a
plus-address to my main GMail address. But I cannot send from a
plus-address. The outgoing email that's saved in the outbox has the
plus-address in the `From' header, but the email that is actually sent
by GMail has my original GMail address in the `From' header.

I'm pretty sure GMail is modifying the email so Claws-Mail can't do
anything about it, but I'm hoping someone here can give me some pointers
on how to send emails from plus-addresses of a GMail account.

[1]: https://learn.microsoft.com/en-us/exchange/recipients-in-exchange-online/plus-addressing-in-exchange-online

-- 
Enan