Thanks, fink.

I know that I can set up separate folders, however, that is not what I am wanting. I would like to keep the emails in completely separate databases, each with their own set of folders. After doing some additional searching, it looks like I might be able to get this capability if I use separate Thunderbird profiles. I will have to do some additional research and hen some experimenting to see if I can get this working.

I try to avoid add-ons, since they are likely to break when updates are applied.