450 4.7.1 Client host rejected: cannot find your hostname

Voltio

Active Member
Oct 17, 2004
32
0
156
For some reason When I send emails I get this message:

2009-10-15 10:07:10 1MyQz0-0002I7-NQ <= [email protected]***.net H=localhost [127.0.0.1] P=esmtpa A=fixed_login:[email protected]***.net S=728 [email protected]***.net
2009-10-15 10:07:10 1MyQz0-0002I7-NQ SMTP error from remote mail server after initial connection: host pe.vmx.terra.com [208.84.244.136]: 450 4.7.1 Client host rejected: cannot find your hostname, [68.168.212.2**]
2009-10-15 10:07:10 1MyQz0-0002I7-NQ == [email protected]******.com R=lookuphost T=remote_smtp defer (0): SMTP error from remote mail server after initial connection: host pe.vmx.terra.com [208.84.244.136]: 450 4.7.1 Client host rejected: cannot find your hostname, [68.168.212.2**]

I did a lot of research and the most frequent answer is setting up the rdns / a records, which it was done already, but the problem persists:

[email protected] [~]# host 68.168.212.2**
2**.212.168.68.in-addr.arpa domain name pointer stable.inter***.net.
[email protected] [~]# host stable.inter***.net
stable.inter***.net has address 68.168.212.2**
[email protected] [~]#

I would really appreciate if you have any suggestions?
 

mtindor

Well-Known Member
Sep 14, 2004
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2009-10-15 10:07:10 1MyQz0-0002I7-NQ <= [email protected]***.net H=localhost [127.0.0.1] P=esmtpa A=fixed_login:[email protected]***.net S=728 [email protected]***.net
2009-10-15 10:07:10 1MyQz0-0002I7-NQ SMTP error from remote mail server after initial connection: host pe.vmx.terra.com [208.84.244.136]: 450 4.7.1 Client host rejected: cannot find your hostname, [68.168.212.2**]
2009-10-15 10:07:10 1MyQz0-0002I7-NQ == [email protected]******.com R=lookuphost T=remote_smtp defer (0): SMTP error from remote mail server after initial connection: host pe.vmx.terra.com [208.84.244.136]: 450 4.7.1 Client host rejected: cannot find your hostname, [68.168.212.2**]

I did a lot of research and the most frequent answer is setting up the rdns / a records, which it was done already, but the problem persists:
Does this only happen when you send emails to [email protected]******.com? I see that pe.vmx.terra.com is the MX for the *****.com domain. I'm guessing that whatever nameservers pe.vmx.terra.com are using for DNS resolution have cached stale information indicating that there is no PTR record for your IP address... even though there is.

If you just made all these changes recently, I'd say give it a day.

You should send email to other places and see if any bounce.. like to a Yahoo or Hotmail or Gmail account. And then if they do arrive in one of those accounts, look at the messages headers of the message once it is in your Yahoo / Hotmail / Gmail account and see if those mail servers had any problem resolving the IP address.

My guess is that it is probably a localized problem with the terra.com mailserver relying upon information from some local DNS resolvers that happen to have stale information in them pertaining to your PTR record....and that time may fix it.

Mike
 

Voltio

Active Member
Oct 17, 2004
32
0
156
Sorbs.net blacklisted

I sent a test message to my yahoo email and I got this.

2009-10-15 12:20:08 1MyT3g-0006qI-KQ <= [email protected]***.net H=localhost [127.0.0.1] P=esmtpa A=fixed_login:[email protected]***.net S=719 [email protected]***.net
2009-10-15 12:20:09 1MyT3g-0006qI-KQ SMTP error from remote mail server after initial connection: host g.mx.mail.yahoo.com [98.137.54.238]: 421 4.7.1 [TS03] All messages from 68.168.212.2** will be permanently deferred; Retrying will NOT succeed. See http://postmaster.yahoo.com/421-ts03.html


I also found out that my ip is blacklisted in Sorbs.net. Could it have something to do with it?
 
Last edited:

cPanelDon

cPanel Quality Assurance Analyst
Staff member
Nov 5, 2008
2,544
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268
Houston, Texas, U.S.A.
cPanel Access Level
DataCenter Provider
Twitter
If the sender's server IP address is on a black-list, such as a DNSBL/RBL, then you will need to contact the administrators of the black-list to determine exactly why your server IP was listed. Once you know how your IP was listed, then you can take additional steps to try preventing the problem from reoccurring; for example, if the DNSBL administrators provide you with the message source of a Spam e-mail your server sent out, then you can use the mail headers to determine which user account is at fault and suspend the user.

Third-party resources for more information:
DNSBL - Wikipedia, the free encyclopedia
Comparison of DNS blacklists - Wikipedia, the free encyclopedia
Spam Links - dnsbl lookup
 

charles.reitz

Registered
Jan 5, 2010
1
0
51
Hello,

I faced the same problem with some servers, all my pointers are correct, do not understand what could be wrong.

Someone could help me.

my domain: seuespaco.net

:eek:

Thank you,
 

cPanelDon

cPanel Quality Assurance Analyst
Staff member
Nov 5, 2008
2,544
11
268
Houston, Texas, U.S.A.
cPanel Access Level
DataCenter Provider
Twitter
Hello,

I faced the same problem with some servers, all my pointers are correct, do not understand what could be wrong.

Someone could help me.

my domain: seuespaco.net

:eek:

Thank you,
So that we can better diagnose the specific situation affecting your e-mail service, please provide a copy of the full e-mail headers (message source) of the bounced e-mail or other e-mail notification that includes the full error message details.
 

phenixak

Member
Dec 3, 2010
10
0
51
Hello,

refresh old topic ...... I have the same problem as above:


-----Original Message-----
From: Mail Delivery System [mailto:[email protected]]
Sent: Tuesday, April 12, 2011 5:24 PM
To: [email protected]
Subject: Mail delivery failed: returning message to sender

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

[email protected]
SMTP error from remote mail server after RCPT
TO:<[email protected]>:
host attis.yyyyyy.pl [82.160.*.*]: 550 5.7.1 Client host rejected:
cannot find your hostname, [46.248.*.*]
Client host rejected: cannot find your hostname, [46.248.*.*]

In what could be the problem?


Best Regards: Adam K.
 

cPanelTristan

Quality Assurance Analyst
Staff member
Oct 2, 2010
7,606
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somewhere over the rainbow
cPanel Access Level
Root Administrator
Does your hostname on the machine resolve?

Code:
dig +short server.domain.com
Above please replace server.domain.com with the server's hostname. If you aren't certain the hostname, try this in root SSH on that machine:

Code:
hostname -f
Does the IP for the machine have a PTR record that also shows the hostname for it?

Code:
dig -x IP#
Above please replace IP# with the server's IP address.
 

phenixak

Member
Dec 3, 2010
10
0
51
Hello,

Everything looks OK.

[email protected] [~]# hostname
hosting.conor.com.pl


[email protected] [~]# dig +short hosting.conor.com.pl
46.248.160.68


[email protected] [~]# hostname -f
hosting.conor.com.pl


[email protected] [~]# dig -x 46.248.160.68

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_5.3 <<>> -x 46.248.160.68
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51145
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;68.160.248.46.in-addr.arpa. IN PTR

;; AUTHORITY SECTION:
68.160.248.46.in-addr.arpa. 86400 IN SOA ns1.conor.com.pl. error.emits.eu. 2011042001 86400 7200 3600000 86400

;; Query time: 0 msec
;; SERVER: 46.248.160.68#53(46.248.160.68)
;; WHEN: Mon Oct 3 19:00:20 2011
;; MSG SIZE rcvd: 110

So what's the problem?

Best Regards: Adam K.
 

cPanelTristan

Quality Assurance Analyst
Staff member
Oct 2, 2010
7,606
33
238
somewhere over the rainbow
cPanel Access Level
Root Administrator
Here's the issue:

;; QUESTION SECTION:
;68.160.248.46.in-addr.arpa. IN PTR

;; AUTHORITY SECTION:
68.160.248.46.in-addr.arpa. 86400 IN SOA ns1.conor.com.pl. error.emits.eu. 2011042001 86400 7200 3600000 86400
You do not have a PTR for that IP, which means the IP does not match the hostname off the server in the IP DNS zone. The IP provider would be the one to correct that issue, since they control the IP zone that would need your PTR set to the hostname for the IP.