In that case, set up Local Folders to be on a separate drive, and put your archives there.

The question was how to do that. I can find no option to define "Local Folders" on any drive other than the drive that also contains the account profile. I know I can copy the profile to another drive and switch between them, but that is WAY too involved to simply archive old email. I also know that I can create a file and call it "Local Folders" on a different drive, but, again, there seems to be no way to direct Thunderbird to send archives to that folder.

What, if anything, am I missing?

- click account settings and scroll down to Local Folders. Note the local directory link - exit thunderbird - COPY (not move) that Local directory folder to the other drive. Name it whatever you wish, if desired - restart thunderbird, click to account settings, and click the dropdown menu on than Local Folders pane and change to the new location. Thunderbird will probably force a shutdown and restart. - verify that all is okay and you can now change your archive to go to the new Local Folders location

TIP: be sure to remember this, as if/when you set up thunderbird on a new PC, you will need to have that same local folders drive accessible.

Thank You! I actually just figured it out for myself. Everything I read lead me to believe that the "Message Store" had to be in the same location as the profile. I just took a chance and changed the location of the "Message Store".