Hi I deleted a very large amount of emails weeks ago and now when I go into mail I cannot get emails as just the spinning thing any ideas ?

Do you have a Time Machine backup to Restore to/from?

https://support.apple.com/guide/mac-help/revert-to-a-previous-macos-version-mh15216/mac

Safe Boot from the HD, (holding Shift key down at startup), does the problem occur in Safe Mode?

Safe mode attempts to repair Disks & clears lots of caches, so if Safe Mode works try again in regular boot.

In Mail's Window Menu, choose Connection Doctor, any red dots for status, if so what is the message?

Then click the Show Details button & Check again.

As a test in a Browser, login to your WebMail.

I cannot receive emails