It’s an email alias service that generates a gibberish albeit unique email which then forwards on any received emails to your specified email inbox.
As far as I can tell there’s no way to link the two together unless you can see where the emails are being forwarded to.
DuckDuckGo offers a similar service (but free), also Proton (simple login) and addy.io (formerly AnonAddy).
Unsure about firefox relay specifically, but I’ve used DuckDuckGo and simple login (after it was acquired by proton) and both have to process the email first before it forwards it onto you. In the case of DDG, they also helpfully strip out any trackers in the email they pick up too.
It’s an email alias service that generates a gibberish albeit unique email which then forwards on any received emails to your specified email inbox.
As far as I can tell there’s no way to link the two together unless you can see where the emails are being forwarded to.
DuckDuckGo offers a similar service (but free), also Proton (simple login) and addy.io (formerly AnonAddy).
Unsure about firefox relay specifically, but I’ve used DuckDuckGo and simple login (after it was acquired by proton) and both have to process the email first before it forwards it onto you. In the case of DDG, they also helpfully strip out any trackers in the email they pick up too.