I am using Qmail and when I am sending mails I am sometimes getting the bellow error in my log for a particular domain.
Jun 22 05:20:47 221832-web1 qmail: 1308738047.397431 delivery 1040373: deferral: CNAME_lookup_failed_temporarily._(#4.4.3)/
Can anyone please tell me what are the factors responsible for such error ?
What are the DNS requests sent by Qmail when sending an email ?
FYI: The patch for the DNS cache size issue is already included in Qmail.