check the 'real' address behind the [accounts@firefox.com] that may jut be covering text, and a scam as you have thought.

Maybe there is a cookie issue. You could try and clear the Firefox cookie and login from scratch.

I mean it is 'the cookie' on your device that sends info to firefox.com when you try and login.

Hi, it's better to sign in to https://accounts.firefox.com/ before the deadline.

Thanks both, very much.

I don't know how to do what Amoun said but I didn't know an address could be covering another one so that's useful. However, I clicked on the link that TyDraniu sent and all seems well there so I'll ignore the email (again) and hope for the best.

Again thank you so much

Stella

"but I didn't know an address could be covering another one so that's useful."

Yes! I can send an email that looks like it could come from anyone. Depends on what you use to view emails on how easy it is to see who the sender really is. Usually there is an option to view the source of the email which shows who the sender is etc. The 'From' / 'Sender' text is easy to spoof.

On the cookie issue, you can view the sites on Fx via Settings > Privacy and Security > Web Site Privacy Preferences > Manage Browsing Data

There you can delete any data stored for a site of your choosing. Which of course means you will have to sign in again etc.

"account will be deleted tomorrow unless I sign in […] I use it nearly every day"

For more information why it might have been sent (e.g. multiple accounts) see Mozilla account deletion due to inactivity and the FAQ there.

For most users though, just going through the account login to post the question here is sufficient to keep it active.

https://support.mozilla.org/en-US/kb/access-mozilla-services-firefox-account#w_what-services-can-i-use-with-a-mozilla-account

The KB article shows what a Mozilla Account is used for as it is possible to use the Firefox web browsers without using a Mozilla Account for anything for two or more years to then get warnings that your Mozilla account will be deleted due to inactivity.