Cannot receive mails from certain domains/servers.

[fluffybunny]

Hi,

I'm currently having some problems getting mails from certain domains.

Does this have anything to do with sendmail or DNS ?

My server configuration is as follows :
Redhat 7.3
Sendmail 8.11.6
BIND 9.2.1

The server is running ipchains as a firewall. All ports are closed except for ports : https, pop3, smtp, domain, ssh.

Mails from other sites seem to come through but certain sites cannot even send mail to my side.
What gives ?

I am cracking my head trying to figure out this problem. Please help.

Regards

 

[Speculus]

I would need to see what errors are being displayed by the senders: messages such as "user unknown" would be helpful.

I had a problem where it took about 24 hrs before a new domainname would propogate through the internet and in meantime some things got thorough to us and some things didn't. It settled down after a short while.

Your ISP should be able to assist.

 

[fluffybunny]

According to the senders, they say they are getting errors :

Server not found.
Server is not a valid TCPIP client.

Problem is that they cannot send to me, but I can send mails to them.

My gut feelings tells me that this may be a problem with sendmail. Can anyone please send me a copy of the sendmail.cf or sendmail.mc file that works. Or at least tell me what flags to enable or disable.

Regards.