Hello,

I have a problem sending mail to 1 specific domain on my new cPanel/WHM VPS with Exim mailserver from my external hosted Exchange account. Sending mails to every other e-mail domain on my VPS works fine, only to that specific domain fails.
But when I use an non-exchange email account to send to that domain, it works perfect.

This is the info in the rejection mail:

Bronserver: mx1.myoutlookonline.com

axel@xxx.eu
mail.xxx.eu #<mail.xxx.eu #5.0.0 smtp; 503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.> #SMTP#
I think the Exim mailserver rejects the mail, because the sending mailserver domain (myoutlookonline.com) is not the same as my e-mail account (mydomainname.be), but in the mail logs on my server I can’t find any notice of the exchange server that connects, or that any mail gets rejected.

I tried adding the IP of mx1.myoutlookonline.com tot the Trusted SMTP IPs and to the /etc/relayhosts, and I tried disabeling some of the ACL Options, but still I get the rejection notice.

So it looks like the problem is the connection from the exchange server to my mailserver.

Anyone has an idea why the mail gets rejected?

Thank you!