> Somehow both of those survived the upgrade from Jessie to Stretch (at a time > when I was not aware of the potential problem), and squirrelmail still works > fine. > > Can I expect that they will also survive the upgrade to Buster?
Yes. I have done that, and the old squirrelmail package remained installed in buster. I don't remember any special effort to keep it, but it was a while ago. You'd better make sure you don't have apt configured to automatically answer yes, so you can choose what gets removed. I can't tell you whether squirrelmail will continue to work in buster. It wasn't working for me, and I removed it before realising my immediate problem was an expired SSL certificate, not squirrelmail itself. -- Cheers, Clive
