I checked $genEmailDisable immediately when the difficulty surfaced and it was already at $genEmailDisable=0; As I said, emails were initially going to users okay and I had made no chages to alter that function. Since my original post I have also opened all other email settings I could find and have set them as so:
I still have no working email now.
Yes, I do realize the difficulty may lie with my hosting service's sendmail and perhaps they have spamtraps. I've had somewhat similar experiences with other things. The fix, through contact with my host's support, was to change my sendmail path to an alternate sendmail setup they have, but do not advertise. Since I did that the problems have totally disappeared. However, with miniBB I apparently cannot alter the path to sendmail, to accomplish this.
Regarding the PHPMailer class, I assume you are saying that it will work with 2.0-RC5? It's paramount that I have reliable email functions. Otherwise, I am going to have to change back to a bulkier forum application.