Question
My mail server shows that it is unable to resolve its own address when it is attempting to send out mail. How can this happen?
Answer
In order for a mail server to be able to send out mail to another server it must first do an MX lookup in DNS in order to discover where to send a particular message.
When it completes this MX lookup the first thing it does is to check to see if the mail server itself appears in these MX records. If it does it must remove itself from the list of records in order to stop mail looping.
The server would then attempt to send the mail to the highest priority MX record available (i.e. the one with the lowest number).
As you can see the mail server must be able to tell who it is itself in order for this process to function correctly. The most likely reason that the server is unable to resolve itself is that the TCP/IP information on the server itself is not set up correctly.
See Also:
- What is DNS?
- What are common DNS configuration issues?
- What are the error codes produced by DNS resolution?
- How should I specify a domain for TCP/IP on Windows servers?
- How should I specify a domain for TCP/IP in Windows 7, Windows 8, Windows Server 2008, Windows XP and Windows Server 2003?
- Why does #GMSClassic# report ‘Loop Detected’?
- What is an MX record?
- I get gethostbyname failures in my logs what does this mean?
- How do I specify a domain for TCP/IP in Redhat Linux?
- What does gethostbyname mean?
- How do I specify a DNS server directly within Gordano products?
- How should I specify a domain for TCP/IP in Windows NT?
Keywords:resolver error code DNS address