My postfix server is rejecting my client: 4.7.25 Client host rejected: cannot find your hostname, [96.9.90.28]Postfix is rejecting some incoming emails (“Client host rejected: cannot find your hostname”)Postfix rejects sender addressPostfix rejects all incoming mail (Client host rejected: Access denied)Postfix/smtpd: Client host rejected: cannot find your hostname450 4.7.1 Client host rejected: cannot find your hostnameS450 4.7.1 Client host rejected: cannot find your reverse hostnamePostfix not detecting hostname or domainMessages with SPF Softfail Not RejectedPostfix: How to accept email with valid SPF but unresolvable hostname?My postfix server rejects my python script - “Client host rejected: cannot find your hostname”
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My postfix server is rejecting my client: 4.7.25 Client host rejected: cannot find your hostname, [96.9.90.28]
Postfix is rejecting some incoming emails (“Client host rejected: cannot find your hostname”)Postfix rejects sender addressPostfix rejects all incoming mail (Client host rejected: Access denied)Postfix/smtpd: Client host rejected: cannot find your hostname450 4.7.1 Client host rejected: cannot find your hostnameS450 4.7.1 Client host rejected: cannot find your reverse hostnamePostfix not detecting hostname or domainMessages with SPF Softfail Not RejectedPostfix: How to accept email with valid SPF but unresolvable hostname?My postfix server rejects my python script - “Client host rejected: cannot find your hostname”
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My postfix host is rejecting my client with this message:
4.7.25 Client host rejected: cannot find your hostname, [96.9.90.28].
From the cli on the postfix server, I get this:
root@civicrm:~# host 96.9.90.28
28.90.9.96.in-addr.arpa domain name pointer 28.90.9.96.sinet.com.kh.
So, there is a pointer record. Why would it be rejected.
I then put in a phony hostname in /etc/hosts with the same IP address and the was accepted and email successfully sent.
I then added 96.9.90.28 28.90.9.96.sinet.com.kh to the /etc/hosts file and it was also accepted.
What could be the problem?
postfix
asked Jun 4 at 2:48
VietyankVietyank
1065
add a comment |
My postfix host is rejecting my client with this message:
4.7.25 Client host rejected: cannot find your hostname, [96.9.90.28].
From the cli on the postfix server, I get this:
root@civicrm:~# host 96.9.90.28
28.90.9.96.in-addr.arpa domain name pointer 28.90.9.96.sinet.com.kh.
So, there is a pointer record. Why would it be rejected.
I then put in a phony hostname in /etc/hosts with the same IP address and the was accepted and email successfully sent.
I then added 96.9.90.28 28.90.9.96.sinet.com.kh to the /etc/hosts file and it was also accepted.
What could be the problem?
postfix
asked Jun 4 at 2:48
VietyankVietyank
1065
Your email client should be configured to send mail on port 587, not port 25.
– Michael Hampton♦
Jun 13 at 0:17
add a comment |
My postfix host is rejecting my client with this message:
4.7.25 Client host rejected: cannot find your hostname, [96.9.90.28].
From the cli on the postfix server, I get this:
root@civicrm:~# host 96.9.90.28
28.90.9.96.in-addr.arpa domain name pointer 28.90.9.96.sinet.com.kh.
So, there is a pointer record. Why would it be rejected.
I then put in a phony hostname in /etc/hosts with the same IP address and the was accepted and email successfully sent.
I then added 96.9.90.28 28.90.9.96.sinet.com.kh to the /etc/hosts file and it was also accepted.
What could be the problem?
postfix
asked Jun 4 at 2:48
VietyankVietyank
1065
My postfix host is rejecting my client with this message:
4.7.25 Client host rejected: cannot find your hostname, [96.9.90.28].
From the cli on the postfix server, I get this:
root@civicrm:~# host 96.9.90.28
28.90.9.96.in-addr.arpa domain name pointer 28.90.9.96.sinet.com.kh.
So, there is a pointer record. Why would it be rejected.
I then put in a phony hostname in /etc/hosts with the same IP address and the was accepted and email successfully sent.
I then added 96.9.90.28 28.90.9.96.sinet.com.kh to the /etc/hosts file and it was also accepted.
What could be the problem?
postfix
postfix
asked Jun 4 at 2:48
VietyankVietyank
1065
asked Jun 4 at 2:48
VietyankVietyank
1065
edited Jun 4 at 2:56
Vietyank
asked Jun 4 at 2:48
VietyankVietyank
1065
asked Jun 4 at 2:48
VietyankVietyank
1065
asked Jun 4 at 2:48
VietyankVietyank
1065
1065
Your email client should be configured to send mail on port 587, not port 25.
– Michael Hampton♦
Jun 13 at 0:17
add a comment |
Your email client should be configured to send mail on port 587, not port 25.
– Michael Hampton♦
Jun 13 at 0:17
Your email client should be configured to send mail on port 587, not port 25.
– Michael Hampton♦
Jun 13 at 0:17
Your email client should be configured to send mail on port 587, not port 25.
– Michael Hampton♦
Jun 13 at 0:17
add a comment |
1 Answer
1
active
oldest
votes
You postfix configuration has reject_unknown_client_hostname which rejects mails because 28.90.9.96.sinet.com.kh. doesn't resolve back to 96.9.90.28.
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
What is the process used by this directive to determine that 28.90.9.sinet.kh doesn't resolve back to 96.9.90.28? I thought it just looked for a PTR record
– Vietyank
Jun 14 at 1:56
I have a feeling this was a temporary thing (internet in Cambodia can be flaky). I put the directive back in and took the entry in /etc/hosts out and mail is going out without fail.
– Vietyank
Jun 14 at 2:13
@Vietyank , my answer contains a link to the postfix documentation which describes what this check does.
– AlexD
Jun 14 at 9:03
Yes. I see that. What is the process that causes the name mapping to fail?
– Vietyank
2 days ago
@Vietyank the process is the domain name resolution, when DNS server fails to return expected answer then this process fails. In your case DNS servers were returning NXDOMAIN for 28.90.9.96.sinet.com.kh.
– AlexD
2 days ago
add a comment |
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1 Answer
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1 Answer
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You postfix configuration has reject_unknown_client_hostname which rejects mails because 28.90.9.96.sinet.com.kh. doesn't resolve back to 96.9.90.28.
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
What is the process used by this directive to determine that 28.90.9.sinet.kh doesn't resolve back to 96.9.90.28? I thought it just looked for a PTR record
– Vietyank
Jun 14 at 1:56
I have a feeling this was a temporary thing (internet in Cambodia can be flaky). I put the directive back in and took the entry in /etc/hosts out and mail is going out without fail.
– Vietyank
Jun 14 at 2:13
@Vietyank , my answer contains a link to the postfix documentation which describes what this check does.
– AlexD
Jun 14 at 9:03
Yes. I see that. What is the process that causes the name mapping to fail?
– Vietyank
2 days ago
@Vietyank the process is the domain name resolution, when DNS server fails to return expected answer then this process fails. In your case DNS servers were returning NXDOMAIN for 28.90.9.96.sinet.com.kh.
– AlexD
2 days ago
add a comment |
You postfix configuration has reject_unknown_client_hostname which rejects mails because 28.90.9.96.sinet.com.kh. doesn't resolve back to 96.9.90.28.
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
What is the process used by this directive to determine that 28.90.9.sinet.kh doesn't resolve back to 96.9.90.28? I thought it just looked for a PTR record
– Vietyank
Jun 14 at 1:56
I have a feeling this was a temporary thing (internet in Cambodia can be flaky). I put the directive back in and took the entry in /etc/hosts out and mail is going out without fail.
– Vietyank
Jun 14 at 2:13
@Vietyank , my answer contains a link to the postfix documentation which describes what this check does.
– AlexD
Jun 14 at 9:03
Yes. I see that. What is the process that causes the name mapping to fail?
– Vietyank
2 days ago
@Vietyank the process is the domain name resolution, when DNS server fails to return expected answer then this process fails. In your case DNS servers were returning NXDOMAIN for 28.90.9.96.sinet.com.kh.
– AlexD
2 days ago
add a comment |
You postfix configuration has reject_unknown_client_hostname which rejects mails because 28.90.9.96.sinet.com.kh. doesn't resolve back to 96.9.90.28.
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
You postfix configuration has reject_unknown_client_hostname which rejects mails because 28.90.9.96.sinet.com.kh. doesn't resolve back to 96.9.90.28.
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
answered Jun 12 at 21:03
AlexDAlexD
4,74021726
4,74021726
What is the process used by this directive to determine that 28.90.9.sinet.kh doesn't resolve back to 96.9.90.28? I thought it just looked for a PTR record
– Vietyank
Jun 14 at 1:56
I have a feeling this was a temporary thing (internet in Cambodia can be flaky). I put the directive back in and took the entry in /etc/hosts out and mail is going out without fail.
– Vietyank
Jun 14 at 2:13
@Vietyank , my answer contains a link to the postfix documentation which describes what this check does.
– AlexD
Jun 14 at 9:03
Yes. I see that. What is the process that causes the name mapping to fail?
– Vietyank
2 days ago
@Vietyank the process is the domain name resolution, when DNS server fails to return expected answer then this process fails. In your case DNS servers were returning NXDOMAIN for 28.90.9.96.sinet.com.kh.
– AlexD
2 days ago
add a comment |
What is the process used by this directive to determine that 28.90.9.sinet.kh doesn't resolve back to 96.9.90.28? I thought it just looked for a PTR record
– Vietyank
Jun 14 at 1:56
I have a feeling this was a temporary thing (internet in Cambodia can be flaky). I put the directive back in and took the entry in /etc/hosts out and mail is going out without fail.
– Vietyank
Jun 14 at 2:13
@Vietyank , my answer contains a link to the postfix documentation which describes what this check does.
– AlexD
Jun 14 at 9:03
Yes. I see that. What is the process that causes the name mapping to fail?
– Vietyank
2 days ago
@Vietyank the process is the domain name resolution, when DNS server fails to return expected answer then this process fails. In your case DNS servers were returning NXDOMAIN for 28.90.9.96.sinet.com.kh.
– AlexD
2 days ago
What is the process used by this directive to determine that 28.90.9.sinet.kh doesn't resolve back to 96.9.90.28? I thought it just looked for a PTR record
– Vietyank
Jun 14 at 1:56
What is the process used by this directive to determine that 28.90.9.sinet.kh doesn't resolve back to 96.9.90.28? I thought it just looked for a PTR record
– Vietyank
Jun 14 at 1:56
I have a feeling this was a temporary thing (internet in Cambodia can be flaky). I put the directive back in and took the entry in /etc/hosts out and mail is going out without fail.
– Vietyank
Jun 14 at 2:13
I have a feeling this was a temporary thing (internet in Cambodia can be flaky). I put the directive back in and took the entry in /etc/hosts out and mail is going out without fail.
– Vietyank
Jun 14 at 2:13
@Vietyank , my answer contains a link to the postfix documentation which describes what this check does.
– AlexD
Jun 14 at 9:03
@Vietyank , my answer contains a link to the postfix documentation which describes what this check does.
– AlexD
Jun 14 at 9:03
Yes. I see that. What is the process that causes the name mapping to fail?
– Vietyank
2 days ago
Yes. I see that. What is the process that causes the name mapping to fail?
– Vietyank
2 days ago
@Vietyank the process is the domain name resolution, when DNS server fails to return expected answer then this process fails. In your case DNS servers were returning NXDOMAIN for 28.90.9.96.sinet.com.kh.
– AlexD
2 days ago
@Vietyank the process is the domain name resolution, when DNS server fails to return expected answer then this process fails. In your case DNS servers were returning NXDOMAIN for 28.90.9.96.sinet.com.kh.
– AlexD
2 days ago
add a comment |
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Your email client should be configured to send mail on port 587, not port 25.
– Michael Hampton♦
Jun 13 at 0:17