I hope you will reconsider this decision. Switching user environments is tiresome, and you have to remember to update the archives whenever the database format changes.
Personally, I'd prefer it if PowerMail used separate databases for each folder and subfolder. I can probably continue using PowerMail for a year or so - if I keep compacting the database - but eventually I'll have to switch to a different program. My database is currently 997.8 MB. Before it got compacted, it was 1.78 GB. Jeremy