Have you logged in to Gmail directly, through the web page recently? Checked for permissions, full folders,data limits etc?

Yes all looks okay, the puzzling question is why one account is able to be loaded and works fine and when loading the 2nd account it tells me "Configuration found in the Mozilla ISP database" and then when it checks password "Unable to log in at server. Probably wrong configuration, username or password" I have checked the configuration between the 2 accounts and changed the password again to no avail.

You were able to get your emails through the web page I take it. And is the problem for both sending and receiving emails? You say you've checked the settings. The automated setups are often unreliable as that ISP database can be out of date or just plain wrong. Have you manually checked every setting in TB. And compared it to what your supplier says it needs to be. (Not just your other account). And checked for typing errors and spaces.

Receiving Account type - pop or imap Server name - e.g. pop dot. whatever. ispname or imap. whatever etc Security setting- SSL or whatever Authentication method - normal password or something else Port number - 995 or whatever Sending servername - smtp. gmail. com or whatever Port number 465 or whatever username - full email address or whatever Authentication method - Security ssl/tls or whatever

Thanks for your reply. Gmail web page works fine on both accounts also one of the gmail accounts works fine on Tbird. I have tried everything you mentioned above and still no joy getting gmail to communicate with other account on Tbird.