DNS/MX issue

[xunil321]

Dear all,

our problem is that certain MX/DNS resolutions are not working properly for external users trying to send us
email.

For example, mail users at yahoo.com are getting rejected when trying to send an email to us at "123@example.com".
This mail is rejected as the user "123@

http://WWW.example.com"

as
not a valid email address.
It appears that YAHOO is resolving our CNAME and although
people are trying to send to @example.com it is being re-
solved to @

http://WWW.example.com

which our mail server rejects.

Amazingly mails for example from hotmail.com, gmail.com or
mail.com are working!

Would be great to find here a solution and/or an expla-
nation for this instance.

THX, Rainer

 

[elgrandeperro]

Did you happen to put a CNAME for example.com? I would change this to an A record if so.

 

[twiSSt]

You may want to contact Yahoo, they have had ongoing issues with correctly configured mailservers. The rejection notice may actually lead you to believe there is something wrong with your config, but in fact it may be one of their policies.

I had several clients that yahoo required they submit a "white listing request".


Twist

===========================================
Everything will be OK in the end.
If it's not OK, then it's not the end

 

[xunil321]

@elgrandeperro:
Do you mean in that case to have two A records with the same
IP address?

 

[elgrandeperro]

Having 2 A records with the same IP is not illegal and is useful. That is how named based virtual hosting works, for instance in Apache.

Actually, a CNAME ( I don't think) could not be inserted because the lefthand side would already have a value for the domain and that is illegal for a CNAME. So never mind, the error must be in how the yahoo mta is handling the message.