Firefox Addon?

Is there a Firefox addon, even an unofficial one, that allows mail to be checked? Like “Checker Plus for Gmail,” where you can be notified of new emails, read, reply.
I been trying to find one, but if there is one out there then maybe I can get find it online. Only a billion plus web pages out there.

Hello. Try this addon. He not only checks mail, but also messages from social networks and many services.

I appreciate the link. Trying to figure how to get this to work with Disroot.

Naw, I just can not seem to get it to work with Disroot.