This is what happens when the other end stops responding for some reason (maybe timeout). It appears that the sender mailserver is not happy to wait for 20 seconds for your mailserver to send Recipient ok response.
Here's what happens:
Step 1: Sending mailserver sends MAIL FROM command
Mon 2007-11-26 19:19:26: <-- MAIL From:<crispinspaeth@mac.com> SIZE=3901
Step 2: Your servers does DNSBL lookups. It takes 20 seconds.
Step 3: Your mailserver sends Sender ok response
Mon 2007-11-26 19:19:46: --> 250 <crispinspaeth@mac.com>, Sender ok
Step 4: Your mailserver discovers that the connection has been terminated.
Mon 2007-11-26 19:19:46: Error reading from socket!
Basically, some time during the 20 secods it took your server to do the DNSBL lookup, the other site closed the connection. RFC2821 says that the connection should stay open fot 10 minutes, but some mail servers are not RFC-compliant.
Questions&Suggestions:
- Does the error affect all incoming emails or only some? Is it linked only to certain mailservers?
- Try temporarily disabling DNSBL lookups to see if the error goes away.
- Try whitelisting domains/IP that cause this problem from DNSBL
Here's what happens:
Step 1: Sending mailserver sends MAIL FROM command
Mon 2007-11-26 19:19:26: <-- MAIL From:<crispinspaeth@mac.co
Step 2: Your servers does DNSBL lookups. It takes 20 seconds.
Step 3: Your mailserver sends Sender ok response
Mon 2007-11-26 19:19:46: --> 250 <crispinspaeth@mac.com>, Sender ok
Step 4: Your mailserver discovers that the connection has been terminated.
Mon 2007-11-26 19:19:46: Error reading from socket!
Basically, some time during the 20 secods it took your server to do the DNSBL lookup, the other site closed the connection. RFC2821 says that the connection should stay open fot 10 minutes, but some mail servers are not RFC-compliant.
Questions&Suggestions:
- Does the error affect all incoming emails or only some? Is it linked only to certain mailservers?
- Try temporarily disabling DNSBL lookups to see if the error goes away.
- Try whitelisting domains/IP that cause this problem from DNSBL