MX/AAAA problems

[W. Richard Stevens]

I have been having intermittent email problems for the past months
that I have finally tracked down.  Most hosts could send email to my
kohala.com domain without a problem, but a few had continual problems.

I have finally tracked the problem down to an MX record that points to
a host with a AAAA record.  The MX record was the one with a higher
preference, and it was never used, but just the presence of a AAAA
record for that host causes some mailers/nameservers to gag (and say
the domain is unresolvable).  The AAAA record was being returned by
my nameserver as additional records for either an ANY query or an MX
query.  mcimail.com and mail12.digital.com are two of the servers
that could not send me email.

This is just a warning to others on the 6bone to avoid this problem.
I know many sites are placing all the AAAA records into a separate
.ipv6 subdomain, which solves the problem (or at least makes it a
local problem), but at some point more of these AAAA records that
older servers cannot grok are going to filter up.

	Rich Stevens
I have been having intermittent email problems for the past months
that I have finally tracked down.  Most hosts could send email to my
kohala.com domain without a problem, but a few had continual problems.

I have finally tracked the problem down to an MX record that points to
a host with a AAAA record.  The MX record was the one with a higher
preference, and it was never used, but just the presence of a AAAA
record for that host causes some mailers/nameservers to gag (and say
the domain is unresolvable).  The AAAA record was being returned by
my nameserver as additional records for either an ANY query or an MX
query.  mcimail.com and mail12.digital.com are two of the servers
that could not send me email.

This is just a warning to others on the 6bone to avoid this problem.
I know many sites are placing all the AAAA records into a separate
.ipv6 subdomain, which solves the problem (or at least makes it a
local problem), but at some point more of these AAAA records that
older servers cannot grok are going to filter up.

	Rich Stevens