Cool idea - not new but convenient. Price is worth trying premium. Two concerns:

1) Custom email domains are susceptible to email spamming since you simply create a new address as you like. I would give up a little flexibility to ensure no one could simply create an alias email address on the fly. This would mean creating the alias first in the extension or interface, assigning a real email address and then use the alias on a site. This way spammers or bots couldn't just make a whole bunch of aliases connected to your domain. While I can appreciate the flexibility to create a new alias quickly this comes at a cost and is subject to abuse.

2) How can I manage my aliases using a mobile device? I haven't figured this out yet if it is indeed possible.

Das Tool ist eine gute Idee. Es unterstützt normale Benutzer das Internet einfach mal zu nutzen ohne dass gleich eine irre Datenflut an Marketing-Szenen auf einen einprasseln.
Nur fehlt es noch etwas an Usability:
* Nach der Installation sollte beim Klick auf das Symbol in der Add-On-Leiste die Liste der generierten Relay-Mails zu sehen sein, wo ich mit einem weiteren Klick mir eine Mail kopieren kann. Gleiches gilt für die Auswahl im E-Mail-Feld. Die Option jedes Mal eine neue Mail-Adresse erstellen zu lassen ist zwar schön, aber nicht wirklich immer gewollt.

I am trying to verify my email on a site i signed up for and it said it sent it for me to verify but Yahoo does not have the verification. Not even in the spam folder. So i cant try out the free trial correctly before deciding to purchase the subscription. FF sent me here to report that it didn't work but this rating is the only thing i see to contact Mozilla to report it. Great concept that I would consider using after my 5 trial uses...if i could figure out how it worked.

A nice idea, but you should explain that it's not completely free right at the beggining. It feels like you're mocking me when after reading everything I enter and realise I have 5 free tries and no more...

The drop down menu should contain options to copy and edit all aliases

J'utilise Firefox relay depuis une semaine mais je ne reçois pas les messages sur les alias. Pas très pratique en cas de commande sur internet...Donc soit je n'ai pas compris comment ça marche soit ça ne marche pas.

noch unbekannt

A lot of sites won't accept @foo.mozmail.com. They flag the second "." as being invalid. It would be nice if the separator between my domain and "mozmail.com" could be a "-"

je decouvre a l'instant,plus qu'a la tester en somme....