550 5.7.1 Postfix:Access denied. IP name lookup failed

Niceman2005 · 09-10-2007, 03:50 AM

Hi friends,

I got this error when i try to send to one particular address only.

The Postfix program

<abc@fff.com>: host mx.fff.com[111.5.210.159] said: 550
5.7.1
Access denied. IP name lookup failed [210.177.17.27] (in reply to
MAIL FROM command)

Any idea what is wrong? the rest of the addresses are fine, only this one particular address isn't working...

Please help..
thanks ...

AlucardZero · 09-10-2007, 06:20 AM

It's one of your client or server restrictions, probably one of the reject_unknown* options. Post the output of postconf -n if you can't find it.

Niceman2005 · 09-10-2007, 07:28 PM

Hi Alucard zero,

thanks for your prompt reply.I tried to check, i can't find any option that is blocking the sending to the address. And only sending to two particular address has such problem.
Here it is the output of postconf:

smtpd_client_restrictions = check_sender_access ldap:senders, check_sender_access ldap:udnsenders
check_client_access hash:/etc/postfix/reject_domains,
check_sender_access hash:/etc/postfix/reject_senders, reject_unknown_sender_domain

smtpd_data_restrictions = reject_unauth_pipelining, permit

smtpd_helo_required = yes

smtpd_recipient_restrictions = check_helo_access hash:/etc/postfix/reject_helo,
check_sender_access ldap:senders,
check_sender_access ldap:udnsenders,
check_sender_access hash:/etc/postfix/reject_senders, check_client_access hash:/etc/postfix/reject_domains, permit_mynetworks,
reject_unauth_destination,
ldap:lanonly,
ldap:udnlanonly,

smtpd_restriction_classes = intranet, lanonly, full, campuseronly

smtpd_sasl_auth_enable = yes

smtpd_sasl_local_domain =

smtpd_sender_restrictions =
check_sender_access hash:/etc/postfix/camp_users
transport_maps = hash:/etc/postfix/transport
unknown_local_recipient_reject_code = 450

Niceman2005 · 09-11-2007, 10:12 PM

Hi,

I realised the problem i mentioned before is somehow related to postfix itself because i have a newly setup postfix with no filtering configuration at all, whenever i send mail to the problematic address, it bounce back almost within 2 seconds. Still couldnt figure out what in the postfix is blocking the mail to the address.

Then now i face another problem with "another address", this one returns the error after say 15 mins, not immediately, so i supposed it has reached the destination and somehow maybe get rejected there. It returns the following message which i can't really understand what i need to do to resolve it:

error message as below:

The Postfix program

<chrisvanackeren@comcast.net>: host gateway-r2.comcast.net[216.148.227.126]
said: 521-EHLO/HELO from sender 210.187.17.21 does not map to
mail.shinyang.com.my in DNS 521-sending machine name must be provided
as a
fully 521-qualified domain via EHLO/HELO command. 521-see section
4.1.1.1
and 4.1.4 of RFC 2821 521 521: Please see
http://www.comcast.net/help/faq/inde...il_Policy18784
for
more information. (in reply to MAIL FROM command)

Please guide me on how to solve this problem if possible...thanks.
I am sure none of my filtering rule has mistakenly filter the mail address...

thanks for taking time reading my mail...

AlucardZero · 09-12-2007, 06:46 AM

Code:

alucard@organa:~$ host mail.shinyang.com.my
mail.shinyang.com.my has address 210.187.17.18
alucard@organa:~$ host 210.187.17.21
Host 21.17.187.210.in-addr.arpa not found: 3(NXDOMAIN)
alucard@organa:~$ host 210.187.17.18
Host 18.17.187.210.in-addr.arpa not found: 3(NXDOMAIN)

Read the link it provided you.. you have to make it so that your IP resolves.