Inbound bouncing

[nink]

In-bound mail keeps getting bounced, but out-bound is fine.

I have not changed one single iota of my configuration since April 2004, so this is flumoxing my.  All partitions are fine, all under 50% utilization.

in /var/log/qmail/send/current all inbound messages get have the same message

--- begin ----------------------------------
"delivery nnnn: failure:  Sorry,_I_couldn't_find_any_host_named_mail.myhost.com._(#5.1 .2)
status: local 0/10 remote 0/255
triple bounce: discarding bounce/1788
end msg 1788
--- end   ----------------------------------

I have not altered my DNS service either.  The host name of the machine is mail.ninksink.com.  It resides on an internal network with a router/firewall facing the wild.  I have not changed the port-forwarding of the r/f at all either.

I noticed in the older logs that this occured in the past for a couple of days.  Nov 1st and 4th of 2004 to be exact.

My assumption is that this could be a DNS issue.  I don't run an internal dns.  My MX records on everydns are

------ begin ---------------------
myhost.com 20427 IN MX 10 mx.myhost.com.
mx.myhost.com. 20427 IN A 66.666.66.666
------ end -----------------------

Now I never had a record mail.myhost.com ever and mail was working fine, do I suddenly need this DNS record???  Hmmmm.

I have re-booted my server and still the problem exists.  It has been so since 12/11/2004.....  

This is odd to me at least.

Any and all help is greatly appreciated.