I am having a problem mailing one of my clients. I am fairly sure that the problem is on his side but he assures me he can receive emails from everybody else.
Here is the message I get:
Of course, I can send to everybody else except to him... so who is in the wrong?
<email@example.com>: host mail.example.be[18.104.22.168] said: 550 sorry, no mailbox here by that name. (#5.7.17) (in reply to RCPT TO command)
I did a little research and found the following which seems all wrong to me but hey, he gets emails so maybe I am in the wrong.
I checked to make sure the IP above did point to the clients domain (example.be)
Now I see it points to OVH which is a French hosting provider. So where does the domain name point to?
$ host 22.214.171.124
Now I try and telnet to test it and find out that there is yet another hosting provider 'hebergeons.be':
$ dig mail.example.be
mail.example.be. 86400 IN A 126.96.36.199
The domain points to another IP than the one mentioned in the error. So what is my clients MX record pointing to?
$ telnet mail.example.be 25
Connected to mail.example.be.
Escape character is '^]'.
220 ns1.hebergeons.be ESMTP Postfix
It's pointing to Scarlet which is a Belgian ISP.
$ dig example.be MX
example.be. 86400 IN MX 10 mx.scarlet.be.
and what's the IP for the server?
$ dig mx.scarlet.be.
mx.scarlet.be. 7200 IN A 188.8.131.52
So to me this clearly indicates some serious misconfiguration but then again, I'm no mail guru (yet ).
Does anyone have a clue why he can receive emails with such a setup and more importantly as he can clearly get them, why I get the above error?
Any help, explanation, advice is more than welcome. I'm having a hard time sending quotes over gmail!