Firefox mail notifier?

Question

Mozilla Firefox

hope for the collective mind. here is the gmail notifier addon. it displays when the email arrived and the preview.
but I also have soap on mail.ru and protonmail, I can’t find an application with thunderbird functionality (you specify the login \ pass from the mailbox, many different mailboxes)
who uses what.
need gmail, mail.ru

Answer 1

Isn't it easier to collect all the mail in one box? Now almost any service can collect mail from others.
I also have several addresses, but everything is eventually aggregated into gmail - very convenient. One mobile app, one browser client. You can automatically sort them into different labels upon receipt.