On 8/13/2010 1:31 PM, jason hirsh wrote:
On Aug 13, 2010, at 2:22 PM, Wietse Venema wrote:
jason hirsh:
I am apparently having an issue with some servers whose
mail is being
rejected because of
reject_unknown_hostname
the reject was shown here
Aug 11 00:21:36 xxxxxxx postfix/smtpd[96422]: NOQUEUE:
reject: RCPT
from mail01a.yesbank.com[65.196.66.182]: 450 4.7.1
<MTL01PPSMTP1.YESBANK.COM>: Helo command rejected: Host not
found;
from=<pbona...@yesbank.com> to=<di...@witheld.com> proto=ESMTP
...
but no reject message went out... Is there a way I can
esnure an
error message goes out to the sender???
No reject message is sent out because your server answers
with SMTP
reply code 450. This corresponds with a "Try Again" class
error.
The SENDING MTA will give up after trying for several days.
Only then
will the sending MTA inform sender that the message is
undeliverable,
The 450 reply code means that the hostname lookup failed
because
Postfix received no reply when it looked up the client
hostname,
or when it tried to verify that the name really resolves to the
client IP address.
Ahh so where my server will try for 5 days before giving up
... the sender's will try for a period too THEN notify him..
Thanks.. now that I can sell.....
if I can't get the clients to agree I would have to drop this
restriction
this combined with Larry Stones comment on the Back Scatter
Issues is of a tremendous help
thanks to all
Wietse
Check your setting of unknown_hostname_reject_code. The
default is 450; you should change it to 550. (So that
affected senders will get immediate feedback that their mail
won't be accepted, rather than their server retrying for days.)
http://www.postfix.org/postconf.5.html#reject_unknown_helo_hostname
http://www.postfix.org/postconf.5.html#unknown_hostname_reject_code
You'll also need to maintain a whitelist of clients that fail
this test that you want to receive mail from. Maybe you
already do that.
-- Noel Jones
