Exim Email Problem: 450 4.7.1 Client host rejected: cannot find your reverse hostname

[m0rpheu5]

Hello guys, i´m having problems, to send email for some email providers, in all cases that the message stay on my mail queue for 48-72h i got this message when i try to deliver it now:

450 4.7.1 Client host rejected: cannot find your reverse hostname

What could be? i Have RDNS, SPF, DomainKeys, and i don´t know what could be anymore.

Could anybody help me to fix this issue?

Thanks

[Infopro]

Might be easier to assist with the actual domain name posted. If thats not possible you may want to open a ticket to your host or contact cPanel directly.

[m0rpheu5]

my actual domain is icnetwork.com.br, many of the clients that i´m sending is hosted in the Locaweb provider (locaweb.com.br), but sometimes i got the same problem with users that is not hosted on there, but normally is.

Thanks

[Infopro]

/http://www.intodns.com/icnetwork.com.br

There does seem to be an issue with the domain.

[m0rpheu5]

I didn´t see any issue, what issue did you find? i have others server that appears as yeallow equal my domain, and there is no problem.

[Infopro]

Any warning should be looked into.

[cPanelTristan]

Can you please provide the full error message you are getting that includes what IP and hostname it believes isn't resolving properly?

The icnetwork.com.br domain's IP of 186.251.87.30 does return a PTR of br01.icnetwork.com.br which is the port 25 telnet response for the IP as well, so I don't see where there isn't an rDNS functioning.

[m0rpheu5]

Ok, follow below two emails that i´m getting error to send emails.

delivering 1Qjs98-0000zQ-0H
Connecting to mx.a.locaweb.com.br [186.202.4.42]:25 ... connected
SMTP<< 450 4.7.1 Client host rejected: cannot find your reverse hostname, [186.251.87.30]
SMTP>> QUIT
LOG: MAIN
SMTP error from remote mail server after initial connection: host mx.a.locaweb.com.br [186.202.4.42]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [186.251.87.30]
LOG: MAIN
== financeiro@higiemix.com.br R=dk_lookuphost T=dk_remote_smtp defer (0): SMTP error from remote mail server after initial connection: host mx.a.locaweb.com.br [186.202.4.42]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [186.251.87.30]

----------------------------------------------------------------------------------------------------------

delivering 1QjrYt-0007tN-Nr
Connecting to mx.a.locaweb.com.br [186.202.4.42]:25 ... connected
SMTP<< 450 4.7.1 Client host rejected: cannot find your reverse hostname, [186.251.87.30]
SMTP>> QUIT
LOG: MAIN
SMTP error from remote mail server after initial connection: host mx.a.locaweb.com.br [186.202.4.42]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [186.251.87.30]
LOG: MAIN
== financeiro@logosst.com.br R=dk_lookuphost T=dk_remote_smtp defer (0): SMTP error from remote mail server after initial connection: host mx.a.locaweb.com.br [186.202.4.42]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [186.251.87.30]

Thanks.

[cPanelTristan]

I think you are going to have to contact whoever runs 186.202.4.42 to ask them to check their resolver. 186.251.87.30 does have an rDNS entry, so their resolver isn't accurate at all in that message:

$ dig -x 186.251.87.30 +short
br01.icnetwork.com.br.