Sorry about the odd Subject line. It should just say 'Deleting an email takes the one below it as well'

Sorry again. I swear that when I read my posts before submitting they were error free but I'm now seeing repeated information and typos, not sure what's going on! So , here goes again hopefully clear & without mistakes - 'This has just started happening today. I noticed that I was seeing mail in my In Box then after some actions I'd look again and some were gone. Then they seemed to appear again later. I also notice specifically that when I click the Delete button to delete from my In Box that it takes the mail below it as well but only the mail that I clicked to delete appears in Trash, the other disappears. Also, after clicking Delete the Message Pane goes blank. Similar to above is that when I forwarded a mail to myself it appeared for a moment in my In Box then disappeared and the In Box display seemed to move around/flash. Then a few minutes later it reappeared in the In Box.

Does problem go away when you start in safe fmode? https://support.mozilla.org/en-US/kb/safe-mode

Hi Wayne Thanks for responding & the suggestion regarding safe mode. I didn't try it yet because when I booted up today the problem seems to have resolved itself - so far. But I have saved the link you sent just in case! If it isn't too much trouble or requiring a lengthy reply and effort - Can I ask if you can suggest either way what I could try if the problem returns and it either does or doesn't do it in safe mode? No worries if it's a hassle to reply I'll cross the bridge if & when I get to it. Regards Paul

To rule out any possible corruption occuring in the Inbox, do the following to clean up the Inbox.

Move all good emails into another folder. delete anything you do not want.

When Inbox is empty: Right click on Inbox and select 'Compact'.

Junk and Deleted folders: Right click on Junk and select 'Empty Junk'. Right click on Junk and select 'Compact'. Right click on Deleted and select 'Empty Deleted'.