On Thu, Mar 10, 2011 at 02:35:56PM -0500, Adam N. Copeland wrote:
> This is happening to many clients that are trying to deliver to my domain.
>
> This is a pretty straightforward example of a connection and failure.
> This is not spam, it's verified legitimate traffic from another .edu
> that successfully delivers to other domains.
>
> Mar 10 12:12:30 pmx4 postfix/smtpd[25758]: [ID 197553 mail.info] connect from
> unknown[128.180.2.160]
> Mar 10 12:12:30 pmx4 postfix/smtpd[25758]: [ID 197553 mail.info] >
> unknown[128.180.2.160]: 220 smtp-in.montclair.edu ESMTP Postfix
> Mar 10 12:17:30 pmx4 postfix/smtpd[25758]: [ID 197553 mail.info] >
> unknown[128.180.2.160]: 421 4.4.2 smtp-in.montclair.edu Error: timeout
> exceeded
So the client just sits there for 5 minutes, saying nothing. This is not
a Postfix problem. There is perhaps a network problem between the client
and your server. Apply the usual network-layer debugging tools.
--
Viktor.
