We have 3 servers:
1) POP / IMAP / MX (incoming SMTP)
2) outgoing SMTP
3) mySQL dedicated
VPOPMAIL + MySQL, SMTP authenticated by POP before SMTP.
Some clients are getting '553 sorry, that domain isn't in my list of
allowed rcpthosts (#5.7.1)'. If a customer get his email on POP, wait
some minutes and then try to send emails by SMTP (server 2), its send
the message without error.
But, the customer is authenticated on server 1 (that stores his IP in a
mySQL table)... this is a bug? What's wrong?
The three servers are on a intranet with gigabit interfaces.