SM used ot have a problem with passwords randomly being blanked.   this has not happened since version 14 until the latest 2 releases.   We have 3 different servers running these releases including all upgraded to latest.  All three have had a random user password blanked in the past 4 weeks.   Please fix this issue immediately.  IT IS NOT OUR SERVERS as nothing has changed on them but your product updates.  They are dedicated mail servers.