Exchange - Delivery Aborted problem

In Exchange using all clients (web, pc outlook, etc. ) when I try to send emails *.com.pl or *.pl  I get:

Delivery to the following recipients was aborted:  my edited recepient = (xxx@yyy.com.pl).  

From: Mail Delivery System [mailto:mail-daemon@comcast.net]
Sent: Friday, July 15, 2016 7:57 AM
To: Stephen, Engel
Subject: Delivery status notification

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients was aborted after 9 second(s):

* xxx@yyy.com.pl

I want to send email to Poland and to my buddy at xxx@yyy.com.pl and email extensions of .com.pl and .pl

Where is my problem at - the exchange level ? I can't find any place that I restricted *.pl How do I fix this?  

Thank you.

Stephen Engel

916-362-8329

sengel@cybrk.com