You certainly have activated the Quick Filter. Quick Filter is disables in trouble shoot mode. To disable it in normal mode just click on the Quick Filter button in the tool bar

Many thanks to Mapenzi, problem solved, obviously a ' user error'

Thanks for your feedback! Why do you mark your proper answer as "Chosen Solution"?

I am not familiar with this forum, or how it works, of course your reply solved the problem, as I thought I said in my reply. On another Board I subscribe to if the reply solved the issue then you would would the answer as 'chosen solution'. sorry that I got wrong.

Despite all the solutions in answer to my previous question about legitimate emails going into the spam folder I still have not managed to get ebay@ebay.com to go into my inbox folder, I keep marking them as 'not spam' but it makes know difference, I have even gone into my webmail and set up a message rule, but to no effect.

Never mind, this happens rather frequently in this forum and I didn't want to blame you! As for your spam problem : save the ebay address in one of your address books. Go to Account settings > Spam settings and check ✔︎ each of your address books (see picture)

I have already tried that !

Is this spam (or junk) identified as such by the Thunderbird self-learning Junk filter or by your email service provider? Perhaps you should move the file training.dat from the Thunderbird profile folder to another location and begin again to train the junk filter