Hi,
It never happened before.
I have to run:
sh /script/fixvpop then qmailctl stop; qmailctl start
Mostlikely there are attempts to change the mysql root password. Thats what I have mentioned earlier.
If thats the case, then your server may become a spamming server soon.
To identify if this activity is going on, just register or make a backup of the table dbadmin, I think. After vpop password got changed or it could not connect, restore that table and you shall see that vpop can connect without any problem.
I have done this and found that it worked because the old enc. password was in there and could connect without problems! When I raised this issue, all did not understand or they neglected.