I am going to be a pest and beat a dead horse, so to speak:
ST posted a flawed update to SmarterMail and went away for a long weekend; apparently nobody from ST bothered to check the forum to see if any issues were reported. This is the real heart of the problem. Bugs happen, for sure. But not paying attention makes things worse.
All the apologies in the world don't help when users and admins have nowhere to go when this happens. And businesses selling SmarterMail as a service or as resellers lost clients. This is not new. This particular issue, however, was a big one.
A few years ago, I had migrated from iMail to SmarterMail, and used SmarterMail's own iMail -> SM conversion tool. Turned out that (unbeknownst to me) the conversion wrote a non-standard directory structure into SM, but SM dealt with this OK, and it worked normally from a user point of view. A bit later on, someone at ST saw all this code in SM that handled the non-standard structures, decided that it was useless and took it out. I installed the next minor upgrade and SM blew up on me and my customer.
Dealing with ST was quite difficult; they never fully explained the issue, but provided some help in straightening things out. But then, they also didn't tell me that after each user was fixed (took me a day's work to get all the users straight, one at a time), the changes would take time to propagate, so I had to figure that out as well - at some point early into this process, ST stopped taking my calls and responding to my emails - even though I had a 10-incident phone service package; leaving most of the cleanup entirely to me. And even though it was then clear what had happened, ST never actually admitted how they caused the problem. That should have been a sign, but I stayed. It is now several years later....
Until these kinds of irresponsible and unprofessional behavior change - and it's doubtful at this point that there will be change - ST will continue to lose customers.