How to revert to version 6 from RC 7

I just installed RC7 and ran into an issue. I’m not yet ready to bail on 7, but I’d like to know how to revert back to version 6 if necessary - without losing any settings, mail, etc.

In the past 2 weeks I switched between 6 and 7c very often - for comparison reasons. To do so you need both 6 final and 7 rc installers (setup) at hand. In your case, to go back from 7rc to 6 you need to uninstall 7rc first (either in Windows / Applications or r/click on the setup icon and uninstall from there). Then, install 6 final. If you want to go back to 7 rc simply install 7 rc (it will overwrite 6).
I never had a problem with losing settings, mails etc.
I originally started using eM Client with 6 final. Then went to 7 beta and rc.