GMail Encryption and other Tips
Encrypt Gmail Extension with Chrome:
Mymail-Crypt for Gmail
Finding messages without labels (see https://raisedbyturtles.org/view-unlabeled-gmail)
Method 1 - Turn off conversation view in settings.
-has:userlabels -in:sent -in:chat -in:draft -in:inbox (from http://sumo.ly/cFz6)
-label:{label1 label2} -label:label-name -label:label-name -in:sent -in:chat -in:inbox -in:draft
(use dashes for labels that have spaces)
Method 2 - Leave conversation mode on in settings.
-has:userlabels -in:sent -in:chat -in:draft -in:inbox packet loss (where packet loss is a specific search term)
Other - try this to ensure archived messages are moved to the local machine and then deleted from Gmail…First use Gmail web interface to identify the messages that need to be moved to the local machine. Use filters above. Then move those messages to the "to_archive" folder on Gmail. Then in Thunderbird copy the messages from that folder to the local machine's archive folder. Then go back to Gmail and select all messages in the "to_archive" folder and delete them.
Re-enable conversation if desired.