RE: POP3 and SMTP slow on Linux since we installed a PIX

[sean.kelly () lanston com]

> From: Robert Graham [mailto:robert_david_graham () yahoo com]
>
> It is because you are blocking incoming 113/identd.
>
> When contacted, the e-mail server first opens up a reverse 
> connect to identd in
> order to log that information. It must first wait for the 
> connection to time
> out before it continues. Annoying, isn't it?

With many products (web servers for example), reverse name resolution can be
turned off, I assume this isn't the case with mail.  Is this because it
might otherwise log a spoofed ip as the ip of the sender, and the reverse
lookup is some measure of protection against this?  What if mail is
forwarded from a host for which reverse dns fails?

Sean