Cannot send email to a specific outside domain

Cannot send email to a specific outside domain from one Exchange server (India).

But:

1) able to send mails from yahoo, gmail etc..

2) able to send mails from other exchange server in US.

AND

Telnet to port 25: response from  Exchange server (India)

 >>Connecting To abc.test.com...Could not open connection to the host, on port 25
: Connect failed

 Telnet to port 25: response from  Exchange server (US) 

  >>Connecting To abc.test.com...Could not open connection to the host, on port 25
: Connect failed

Mail sent to abc.test.com is stuck in a message queue with error: #550 4.4.7 QUEUE.Expired; message expired ##

Undelivered mail comes in Inbox with message "The server has tried to deliver this message, without success, and has stopped trying. Please try sending this message again. If the problem continues, contact your helpdesk."

Please guide me Step by Step.

Thanks Nik.