Unfortunately, I have no idea at all what the gmail recovery tool is. But with a bit of googling I guess you mean this https://support.google.com/mail/workflow/9317561?hl=en You may have used Thunderbird with Gmail for an extended time, but you obviously missed the fact Gmail is different. You have no inbox folder on gmail. You have no folders at all. You have an all mail message store and some messages have a label for inbox, some others might have a label for "important" and some might have both. This extends to all the thinks you call folders. See the Thunderbird user support document for details https://support.mozilla.org/kb/thunderbird-and-gmail#w_gmails-particularities When Gmail makes mail available via IMAP. Google simulate folders on the fly based on the labels assigned to individual emails. Google offer some fairly extensive controls on what labels are offered as IMAP folders. See https://mail.google.com/mail/u/0/#settings/labels There is one constant that has existed for as long as gmail has existed. All mail is in the all mail folder and some of the all mail contents may have an inbox label. Others might have a trash/bin/Deleted label The fact that they are all appearing as unread new messages in the inbox is almost certainly caused by your recovery activity. You do not mention what changes or otherwise you have made to Thunderbird, or what happened to necessitate a full recovery of the last 30 days deletions which probably resets all mail to a new unread state. How you are interacting with Gmail within Thunderbird is really an unknown as you have not shared your settings for the account But you might want to visit this google page and ensure you have the defaults selected for your IMAP folders. https://mail.google.com/mail/u/0/#settings/fwdandpop .