WHMCS sending mail using message id @localhost

[ranojit]

Hi,

I'm using SMTP.  My WHMCS sent me notification mail. I open the original mail and discover that the message ID always contaion @localhost instead of my domain name. It showing something like that,

Message ID	<fkfasdfwerkasjdfiasdfkjadfiasdfaef@localhost>

But it should be like,

Message ID	<fkfasdfwerkasjdfiasdfkjadfiasdfaef@domain.com>

 

When I sent email manually from WHMCS it showing the domain name on the message ID. New client also get my WHMCS mail on spam folder for the first time. But if they mark my mail report not spam it's goes to inbox. I have a fewer clients and my WHMCS sent few email. I have valid SPF, DKIM, DMARC records. My server IP isn't blacklisted.

 

I search everywhere but I didn't find the solution for this. Is there any one can help me?