Re: sendmail error, "MX list for mydomain.com points back to server.mydomain.com"

On 2023-05-18 19:44, Dan Mahoney (Ports) wrote:
> Do you see it?  It’s subtle.
> 
> Your system is asking your own 127.0.0.1 DNS for the AAAA for
> ns.dreamchaser.org (because sendmail attempts ipv6 before it attempts
> ipv4)

ok.

> You forgot a trailing . in your NS records.  Your DNS kicks back that
> “hey, I don’t know about ns.dreamchaser.org” so it gives you an SOA
> record. (answer = 0, authority = 1)
> 
> is doing lookups for ns.dreamchaser.org.dreamchaser.org because of 
> that.
> 
> Post your zone file?

Staring hard, but I still don't see it.
This is a cut down one (removed comments and other hosts)
which still fails.
secondary names have been changed.

# cat dreamchaser.org.zone
;$ORIGIN DREAMCHASER.ORG.
$TTL  3600    ; default expiration time of resources w/o their own TTL 
spec
@ IN  SOA ns.dreamchaser.org. root.dreamchaser.org.  (
         2023051801  ; Serial number of this data
         14400 ; Refresh delta, seconds (4 hrs (recommended))
         3600 ; Retry delta, if refresh fails, seconds (1 hr, 
recommended)
         3600 ; Expire, seconds (1 hrs)
         600 )  ; Minimum time-to-live, seconds (10 min, for testing)
   IN  NS  ns.dreamchaser.org.
   IN  NS  ns.secondary.org.
   IN  NS  ns.other-secondary.com.
dreamchaser.org. IN A 66.109.141.57
ns               IN A 66.109.141.57
dreamchaser.org. IN  MX  10 ns.dreamchaser.org.
dreamchaser.org. IN SPF "v=spf1 +mx -all"
dreamchaser.org. IN TXT "v=spf1 +mx -all"

> Here’s what I think it happening:  (Have a reference here:
> 
> Your system is looking at its own rdns/fdns, and discovering that its
> hostname is ns.dreamchaser.org.dreamchaser.org (probably because your
> primary IP is not present in /etc/hosts).  It attempts to deliver to
> itself, and finds that mail SHOULD come to it (since your
> misconfiguration says your MX is ns.dreamchaser.org.dreamchaser.org
> AND that’s what you resolve to, but ns.dreamchaser.org.dreamchaser.org
> isn’t in /etc/mail/local-host-names.

# cat /etc/hosts
::1                     localhost.dreamchaser.org.   localhost
127.0.0.1       localhost.dreamchaser.org.   localhost
66.109.141.57           ns.dreamchaser.org.          ns

> * Put your primary addresses in /etc/hosts — there are numerous
> documented cases of sendmail ignoring /etc/hosts but it *might* help
> clue it in to your proper hostname at least.

see above

> * Fix your forward and reverse DNS
> * (and in fact, stop faking it out.  Fix it at your hosting provider.
> if your hosting provider is taking this long, find another one)

Not sure what you mean by faking it out?
My isp is my only choice.

Gary