For the junk: is this a Junk folder managed by TB's junk controls, or a Junk folder managed by the mail provider? If it's the latter, you must whitelist or unblock these senders in webmail, perhaps by adding them to webmail contacts. If it's the former, try resetting the training data in Settings/Privacy & Security.

The other issue typically is caused by a faulty mouse that is making a single click into a double-click. See if the same thing happens if you move between messages with the arrow keys (no mouse).

Hi thank you for the response.

The junk folder in question is the one managed by TB, it's below the deleted folder and called Bulk Mail.

I have also tried resetting the training data in Settings/Privacy & Security which has made no difference, the majority of my messages are still ending up in bulk mail. I can't see any way of adding messages to a whitelist in Thunderbird and as I said using the not junk button has no effect.

I mean all my eBay messages come from ebay@ebay.com and all the Facebook messages come from the address starting with Facebook so if there was an option to whitelist I could probably sort the problem.

I just can't understand why I've been using TB for years and this has only started happening now!

Are you sure Bulk Mail is managed by TB? TB only names its folder 'Junk'. Suggest you check webmail for a folder named Bulk Mail and see if it contains the FB and ebay messages.

Okay checking that now. Thanks.