Hi Bill

Firefox will not block you receiving emails - you can access you email account online in the say way that you would with any other browser

If you access you email through another browser and can see the 2FA email, you should see the same email when you log into the same email account in Firefox (you might need to log out of the account in the other browser first).

Thanks Paul for the reply, It does not solve my problem as it may be more complicated. After I raised the issue here I received the emails (2) from Bitdefender about 10 hours later, on my laptop (Mozilla browser) but not on my android phone (Gmail). It looks like it may be a synchronization - setting issue between the ISP server, the phone network provider and Google. I will engage the ISP company that my email address is set up with and hopefully the solution rests with them.