Email delivery problem (only with 1 domain)


Apr 18, 2015
cPanel Access Level
Root Administrator
Hello everybody !
I'm confused today because i've an anormal problem with my emails.

The customer of a competitor (web agency & hosting) came to my office some monthes ago and he wanted to work with us. We signed a contrat and now we work together. A lot of emails was sent beetwen my server and his server without any problem during these days.

2 weeks ago, i sent an email to this competitor to get AuthInfo (to change domain registrar) and technical informations to migrate everything (he learned to that point he had just lost a customer). I have not taken the step to steal the client, he came to me because he was dissatisfied with their service.

Since that day, my client no longer receive any email from my server ! I looked at the delivery report emails and everything looks correct on my side but he doesn't get any mail from me... (i tried to send an email to him from hotmail, gmail, ovh.... and it works fine, all my others customers recieve my emails correctly).

The real problem is that if a customer hosted in their infrastructure attempts to contact me, they will not receive my reply so it could be unfair competition...

Everything makes me think that it blocked the address of my server on his own but I do not want to falsely charge, I would come to prove it. I didn't find any way to do that at this time.

Anyone have an idea ?
Thanks !


Well-Known Member
May 20, 2003
cPanel Access Level
Root Administrator
he doesn't get any mail from me... (i tried to send an email from hotmail, gmail, ovh.... and it works fine).
Sounds to me like your email has been blocked. You could try another email address from the same server I suppose to see if it gets through, if not, your entire domain may be blocked.

Nothing you can do about that from your end, if he has, other than use another email.


Technical Support Community Manager
Staff member
Apr 11, 2011
cPanel Access Level
DataCenter Provider
You will need to have the administrator of the remote server review the mail logs to determine why the message was rejected if it was sent out successfully from the cPanel server.

Thank you.