exim port check
1) IN to OUT port check-
[root@ns1 ~]# telnet mail.xxx.com 25
Connected to mail.xxx.com.//you will get time-out here
Escape character is ‘^]’.
220 host.xxx.net ESMTP Postfix
2)Out to IN port check
check with url http://ping.eu
3)Make sure the ports 25,465,587,110 are open for server x.x.x.x on both side.