* Stuart D. Gathman:
Yeah, and when they removed their records, my mail started bouncing
because I was including earthlink.net so my Dad's email would pass.
Can you tell us if it bounced immediately, or after a couple of days?
Such inconsistencies can easily be caused by regular DNS updates
(because of the propagation delay etc.), and they should result in
temporary failures at the SMTP level (not 5xx errors).
They bounced immediately. With a PermError. Because there was
no longer an SPF record for earthlink.net.
Okay, what probably happened is that check_host() returned Neutral for
earthlink.net because they was no record, and "include:earthlink.net"
didn't match as a result.
I think this is a bug in the specification. An "include" referencing
a domain without any SPF record should result in TempError, not
Neutral. This reduces the risk that legitimate mail is bounced
because the DNS is temporarily out of sync after a DNS update which
involves multiple zones.