[sylpheed:33449] On-demand "From:" Customization?

[Christopher Curzio]

Hello, Sylpheed users.

So I've been a longtime Sylpheed user, and recently I've been doing
some advanced tricks with my mail server in the way of filtering and
subaddressing. As a result, I have a whole bunch of unique e-mail
addresses pointing to a single catchall address with filtering being
done server-side based on the To: address. (Example: mail sent to
foo+amazon at domain.com and foo+ebay at domain.com both go to
foo at domain.com.)

The problem I'm encountering is that sometimes it's necessary to reply
to e-mails from these addresses. In those cases, I've found Sylpheed
to be very lacking. Sylpheed will only send mail from the addresses
associated with configured accounts. An obvious workaround is to
create e-mail accounts for every single mail alias I have, but since
that list is growing every day that is a completely unacceptable
solution.

Again, I'm a longtime Sylpheed user, so I've become very familiar with
the settings and configuration over the years but on the off chance
I'm missing something, I figured I'd ask. Does the functionality exist
in Sylpheed to customize the From: address at mail composition time?

If this functionality exists, it would be great if it could be added.
Even better would be if an option for "Reply as To", so when you reply
to an e-mail the From address is automatically populated with the To
address where the original e-mail was sent.

Side Note: I'm aware that Claws is able to customize the From address
in the compose window, but Claws is overkill for this, repeatedly
broken (OpenSSL in the latest version, anyone?), and frankly I prefer
Sylpheed anyway.

Thanks.