Hi Techies, We are using exchange server 2003 as our mail server, recently I found 1 issue in our server we cannot send mail to any hotmail/live mail accounts except hotmail all other external mails (Gmail, yahoo etc) are working fine. I checked the SMTP queue there are no messages in the queue, I am able receive emails from hotmail but sending is the problem, very strange problem can anybody guide me to get out from this issue ASAP. Thanks in advance for your valuable support. Regards, Phani Kumar .B

~ Do you get any NDR? ~ Verify the communication from Exchange Server to Hotmail manually with telnet... Get the MX record of Hotmail with below article. How to Use Nslookup to Verify MX record configuration http://technet.microsoft.com/en-us/library/aa998082(EXCHG.65).aspx Test the SMTP communication to MX record of gmail as per below article. How to Use Telnet to Test SMTP Communication http://technet.microsoft.com/en-us/library/aa995718(EXCHG.65).aspx ~ Make sure that external lookup resolve the MX record of hotmail correctly from your Exchange server. ~ Do you have reverse DNS configured in Public DNS for your MX record? Many domains require it. ~ You can configure SPF record for you domain, if you didn't do it already... http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/ Amit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com