re :''But the problem is this note add-on is local computer based, meaning other computers don't see the note I created. '' ''Do you have any suggestions on how I can accomplish this task? I want to use this to communicate with my colleagues. '' You are using the one designed to work exactly as you describe. It is designed for single user. The one designed for commercial users would probably offer what you require. https://addons.mozilla.org/en-GB/thunderbird/search/?q=messagenotesplus&appver=&platform= Quote from addon: ''Message Notes Plus allows to add notes to emails. The notes don't affect the email in any way.'' ''They are stored locally on your hard drive.'' '''''The commercial version of the add-on allows to share notes with other users: http://msgnotes.alehro00.com''''' This would be the link as the msgnotes one does not seem to work: http://www.alehro00.com/my-projects/message-notes-plus-shared

Located some info on Tags: http://kb.mozillazine.org/Tags#IMAP https://support.mozilla.org/en-US/questions/1067550