not recieving emails

What version please? Did it happen exactly on a version change? Imap account, or pop account?

how do i find version

Hello there

https://support.mozilla.org/en-US/kb/find-what-version-thunderbird-you-are-using

I’d first check whether the account is still connected properly in Thunderbird. You can find your Thunderbird version through Help → About Thunderbird and share that version here. It’s also worth checking whether the account is configured as IMAP or POP, as that can affect how messages are received. If you recently changed your password or enabled additional security on the email account, re-authentication may also be needed. Once you share the Thunderbird version and account type, it should be easier to narrow down what is preventing new emails from arriving.

Your version ??