our problem is that certain MX/DNS resolutions are not working properly for external users trying to send us
For example, mail users at yahoo.com are getting rejected when trying to send an email to us at "email@example.com".
This mail is rejected as the user "123@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 @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.
I'm not sure how your mail configuration is set up, but you should try doing this:
of course, subsituting your real IP address as x.x.x.x, and using your real domain and mailserver name.
IN MX 0 mail.example.com.
mail IN A x.x.x.x
And dont forget it can take several hours for the changes to be seen by some ISPs.