re : I decided there might be some corruption in the my inbox so I used 'Repair Folder to try and correct this. This just emptied my inbox completely and I cannot get them to display again.

'Repair folder' repairs the index folder as it was out of synch with the real contents of the 'Inbox'. In other words, the emails had already gone, repairing the folder did not remove them.

It is possible that you may have an Anti-Virus product which caused this. The Inbox was scanned and something was flagged, so the AV quarrantined the file. Please note that a 'Folder' displayed in the 'Folder Pane' is an mbox 'File'. Emails are listed one after the other in the order downloaded. An AV product would not necessarilly understand this and simply quarrantines the whole file. If you have set AV up to auto fix and not ask you what to do then it may not be possible to recover file.

I mention AV doing this because in these cases the AV does not effect the index file, hence why it was out of synch with mbox file.

re :'This configuration cannot be verified - is the username or password wrong' . What this means is: either or both of the username or password are wong OR they may be correct but the server settings are wrong OR check the webmail account is set up for 'Less secure apps'

'User Name' should be full gmail email address. Password is the same password you would use for accessing via webmail.

I am using AVG to protect my emails etc. There are no files in the quarantine area so I assume the problem is not there. I had google set up to allow less secure apps and I know this was switched on because I had a notification from Google.

I have carefully checked my user name and password and the server settings are correct. I am also using the latest version of Thunderbird.

Any more suggestions would be welcome.