Hello everyone,
Sorry @Dave, I couldn’t find this thread when i posted my suggestion about easier alias creation. You may want to merge it into this thread, now…
FYI, @poule The problem with aliases and configuring them with your e-mail client is one of the reasons Thunderbird is so great: you can just edit the “From:” field at your guise without any added configuration 
(The only limitation being that your e-mail hosting platform will hopefully reject messages that are using an e-mail address that’s not yours.)
Sincerely,
Vincent