Newsletter Builder mail server issue

Hi,

Our customer site's web server and email server are in different server(different location).

The newsletter builder is built on the web server.

When testing the newsletter everytime.

Their domain email can not got the newsletter.

But any other email(gmail, hotmail, yahoo) are fine with it except their domain email.

Their MIS said their mail server never get the subscribe, confirmation, newsletter emails.


How to test and solve the issue?

Hope can get help.

Thanks!

-Jax H.