NYCPHP Meetup

[Steve Manes]

csnyder wrote:
> Most mail-related problems have nothing to do with the sendmail line
> used by PHP. They are typically problems further downstream in the
> mail system.

A common one is assuming that the localhost mail server is working 
because it accepts the mail from the application.  I see a lot of 
bounces in my mail logs from web sites which ship mail from the 
box-stock and unconfigured sendmail servers on localhost.  These 
machines will often not be registered in DNS or will lack a valid PTR 
record or will greet target server with a generic "HELO 
bogus.site.name".  An increasing number of mail servers are doing DNS 
checks of mail servers as an anti-spam defense.

Case in point:

Jun 11 04:13:55 jack postfix/smtpd[57160]: NOQUEUE: reject: CONNECT from 
unknown[62.160.92.240]: 554 5.7.1 Client host rejected: cannot
  find your hostname, [62.160.92.240]; proto=SMTP