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

On 20/05/2023 2:45 pm, vagabond wrote:
> On 2023-05-19 16:41, Dan Mahoney (Ports) wrote:
>> Any luck?
> 
> Unfortunately, no
> I was going to send the below last night but wanted to try some more 
> things.
> I did, but haven't gotten much useful info.
> 
> On 2023-05-18 16:11, little.analyst892@aceecat.org wrote:
>> On Thu, May 18, 2023 at 03:36:52PM -0700, vagabond wrote:
> 
>>> ;; res_nquerydomain(ns.dreamchaser.org, dreamchaser.org, 1, 28)
>>> ;; res_query(ns.dreamchaser.org.dreamchaser.org, 1, 28)
>>> ;; res_nmkquery(QUERY, ns.dreamchaser.org.dreamchaser.org, IN, AAAA)
>>> ;; res_send()
>>> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 45481
>>> ;; flags: rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
>>> ;;      ns.dreamchaser.org.dreamchaser.org, type = AAAA, class = IN
>>> ;; Querying server (# 1) address = 127.0.0.1


I run sendmail ipv4. Though unless you can correctly resolve ns and mx, 
per the following:

# host -t mx dreamchaser.org; host mail.dreamchaser.org.
dreamchaser.org mail is handled by 10 mail.dreamchaser.org.
mail.dreamchaser.org is an alias for ns.dreamchaser.org.
ns.dreamchaser.org has address 66.109.141.57

sendmail won't receive.  From an earlier email in this thread, querying 
your dns @localhost suggest that where-ever your internet addresses are 
resolved has something wrong.  Sometimes a dot can make the difference ;)

1. To expedite, change /etc/resolv.conf
nameserver WhereYourDNSisPubliclyResolvedNotLocalhost
# EOF
2. Use host or dig to resolve what's required for your sendmail.  host, mx
3. if (2) is working then look at other things natd, firewall rules, 
routing and finally sendmail (its usually an innocent bystander)
4. Fix your local dns, res_query(ns.dreamchaser.org.dreamchaser.org... 
is wrong.

As aside, when setting up other businesses, most sendmail problems that 
I've experienced were dns resolution issues.  I note your PTR record is 
also correct. :)

PS From bitter experience, I place dnl at the end of every sendmail.mc 
statement.