Is MySQL used for storing user information so that we the ISP can use it for tech support , etc. I cannot compile vpopmail with mysql support.You would do better to use MySQL support if you are an ISP
You have a good day now,
because chances are you will have a crap load of users and
it will give you faster account lookups for email. Also you
can use MySQL replication and a NFS server to setup a second
server for failover.
I would bet also having this stuff in MySQL would allow you
to do reports on how many users per domain and last login and
all that kind of stuff as well.. I use MySQL myself for my
user backend on Vpopmail and have not problems with it at all.