On 23 May 2013, at 10:49, Deeztek Support wrote:
On another topic, I had an issue the other day where an outside sender
was trying to send e-mail to an internal recipient and their e-mail
was getting
delayed due to a DNS issue on their end. The exact error was:
(Host or domain name not found. Name service error for name=rotary.org
type=MX: Host not found, try again)
This specific error message is very commonly the result of a resolver
being tricked by purely local IPv6 existence (i.e. auto-configured
interfaces and link-local addresses) into trying to query other DNS
servers over IPv6. All 5 NS records for rotary.org point to names with
both A and AAAA (IPv6) records, which makes that a plausible root cause.