SOLVED Direct inquiry (forked topic)

Robert COLIN

@borzel .
Is just I can't have contact with Olivier. Mail doesn't work. And I would like service from Vates company. I'm sorry to use this way but I tried by all that I can for one month. Sorry for disturbing this post.

stormi

I've forked the topic, since there was no reason to have this discussion on the original topic.

olivierlambert

I'll answer via private chat on the forum

borzel

@Robert-COLIN If you using a self build mail setup, check it first:
550 - 550-Requested action not taken: mailbox unavailable
550 invalid DNS MX or A/AAAA resource record

Sounds like your mail server is not correctly resolving the vates DNS/MX entry. Did you check that on the mailserver?

MajorTom

To vates.fr:

Seems your DNS MX records are CNAMEs (aliases). They should not.

$ host -t mx vates.fr
vates.fr mail is handled by 50 smtp2.vates.fr.
vates.fr mail is handled by 10 smtp1.vates.fr.

$ host smtp1.vates.fr.
smtp1.vates.fr is an alias for mail1.vates.fr.
mail1.vates.fr has address 212.129.1.64

$ host smtp2.vates.fr.
smtp2.vates.fr is an alias for mail2.vates.fr.
mail2.vates.fr has address 212.129.1.118

$ host -a smtp1.vates.fr.
[...]
smtp1.vates.fr.         600     IN      CNAME   mail1.vates.fr.

$ host -a smtp2.vates.fr.
[...]
smtp2.vates.fr.         600     IN      CNAME   mail2.vates.fr.

This can be the reason that some mail servers don't deliver mail to you.

See RFC 2181:

"The domain name used as the value of a NS resource record, or part of
the value of a MX resource record must not be an alias. Not only is
the specification clear on this point, but using an alias in either
of these positions neither works as well as might be hoped, nor well
fulfills the ambition that may have led to this approach. This
domain name must have as its value one or more address records.
Currently those will be A records, however in the future other record
types giving addressing information may be acceptable. It can also
have other RRs, but never a CNAME RR.

Searching for either NS or MX records causes "additional section
processing" in which address records associated with the value of the
record sought are appended to the answer. This helps avoid needless
extra queries that are easily anticipated when the first was made.

Additional section processing does not include CNAME records, let
alone the address records that may be associated with the canonical
name derived from the alias. Thus, if an alias is used as the value
of an NS or MX record, no address will be returned with the NS or MX
value. This can cause extra queries, and extra network burden, on
every query. It is trivial for the DNS administrator to avoid this
by resolving the alias and placing the canonical name directly in the
affected record just once when it is updated or installed. In some
particular hard cases the lack of the additional section address
records in the results of a NS lookup can cause the request to fail."

julien-f

Thank you for your help, we have removed smtp2 which did not exist and changed smtp1 to be an A record instead of CNAME

borzel

@MajorTom cool

MajorTom

You're welcome!
I'm happy I could help a little. I'm grateful for XCP-ng!

Robert COLIN

@MajorTom Thank you now I can send mail to Vates. Thanks julien-f too.

MajorTom

@Robert-COLIN That's great! Good luck :-).