Delay in receiving emails
Fellow debian users--
I recently setup a box to act as a mail (qmail) and DNS (bind9) server.
Because I only have one external IP address, this machine is accesible
through a main server by means of forwarded ports using iptables. For
example, if you telnet into port 25 of my main server, you are actually
opening a connection on the mail and dns server.
My question is that I notice that it often takes long (15min +) to
receive certain emails, and I cannot figure out why. If I send myself an
email (from an external network) by a telnet SMTP session on my main
server, the email appears right away. However, if I send an email to the
same address using Gmail (I replicated the problem in other
clients, but it happen more often with emails sent from Gmail), then it
takes a while to show up. This leads me to think that it may be a
DNS rather than mail problem, but I am not sure.
I'd appreciate any hints or solutions and would very happily follow up
with anyone who is willing to help..