Other than the view offered via 'Message Filters' where you click on the 'Filter Log' button to see the filtered emails in date order of filterd emails with oldest at top.... You can locate file via Thunderbird. In Thunderbird * Help > Troubleshooting information * Under 'Application Basics' - half way is Profile Folders - click on 'Open folder' A new window opens showing contents of the profile name folder. * If pop account click on 'Mail' folder to see contents. * If imap account click on 'ImapMail' folder to see contents At this point you could create a shortcut for the mail account name folder and put it on desktop so in future you can access this folder a bit quicker. * Click on name of account folder to see contents * Scroll down and locate 'filterlog.html' * Right click on file and select 'Open With' and choose eg: Notepad, OpenOffice writer OR if opened using NotepadYou can copy contents and paste them into a suitable program like OpenOffice if you want. Then save that file separately for viewing. However, it's only a copy of current content. It does mean you can select another font or use 'Find' to locate anything like folder name or filter name, but it's not exactly something that gets auto updated. It's a view of file in current state when opened, but does faciliate a means of searching. I would not advise editing directly as anything appended will be using whatever Thunderbird is designed to use. But if you exit Thunderbird first and then right click on filterlog.html and choose 'Edit with Notpad++' it is possible to Add Text which can be read via the 'Filter Log' button. But it's not exactly going to achieve much. Possible to use as a quick marker if you use capitals. It's a lot of effort for no real gain. One benefit of editing is to remove older logs, but keep recent - not an option offered directly in Thunderbird. In Thunderbird via the 'Filer Log' button you can choose to clear the content and start afresh BUT that's it - view something that gets bigger and when you clear it also gets rid of recent logs. But you could use the Edit method to remove just the really old logs and therefore do a partial clearance. Please note you must only edit/remove each paragraph which starts and ends with the open <p> and close </p> and those are inclusive which means you need to know what you are doing as it is written using html. I've just used this to remove everything prior to 1st Jan 2025. So I still have all my recent logs, but the list is less lengthy and easier to view via normal method.