labels DNS,SPF
summary How to Setup DNS record for SPF
How to Setup DNS record for SPF
Please refer http://www.openspf.org/ to setup SPF record.
This is a simply example:
iredmail.org. 3600 IN TXT "v=spf1 mx mx:mail.iredmail.org -all"
or:
iredmail.org. 3600 IN TXT "v=spf1 ip4:202.96.134.133 -all"
Another tip from maxie_ro: http://www.iredmail.org/forum/post5456.html#p5456