Do you use smtp-tls and smtp-auth at the same time?
If Yes, then there are at least TWO reason for slow smtp-session.
The first, DNS-related can be reloved by tcpserver's parameters.
The second, tls-related - by creating temproraly RSA key,
that can be done by executing
# make tmprsadh
at qmail source with applied tls-patch directory...
- when a 512 bit RSA key is provided in /var/qmail/control/rsa512.pem,
this key will be used instead of (slow) on-the-fly generation by
qmail-smtpd. Idem for 512 and 1024 DH params in control/dh512.pem
`make tmprsadh` does this.
try it and see if that helps you
Yuri Nosyrev mailto: nua at slavel dot ru