Nathan Cassano wrote:
> 
> Hi folks,
>         Our website (on an internal NAT'ed network) connects our email
> server (on an external network). The website uses a SMTP PHP class to
> send mail using socket connections. The problem is a delay in connecting
> to the mail server that causes the class to quit prematurely. I fixed
> the problem by adding a function call to sleep(1) after fsockopen() but
> this is a hack. Is there a better way to fix this TCP delay? I tried
> setting the TOS value to Minimize-Delay but I didn't see any difference.
> Any suggestions are welcome.

what happens when you use telnet from the website box to the mail server's
port 25? do you get a delay rec'ving the SMTP banner? Likely has nothing to do
with netfilter...my money's on a paranoid SMTP trying to do a reverse DNS
lookup (or identd?) causing the delay. Maybe there's no PTR record for the NAT
(public) IP of the website? Maybe your SMTP server has a big-ish list of DNS
hosts to try before it finally timesout?
--
Doug

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