Hi Are you running this on the Exchange server or from your desktop? The 550 5.7.1 means that it will not relay the message from the sending machine, which in this case would probably be your client. You need to have a receive connector that allows your client's IP to relay through Exchange. Cheers, Steve

On Sun, 19 Feb 2012 09:24:34 +0000, Lee John wrote: > > >Dear all, > >I run the following command under the COMMAND PROMPT: > >telnet mycompany.com.hk 25 helo mycompany.com.hk mail from :aa@mycompany.com.hk {My company Email account} rcpt to:finny.lee@yahoo.com.hk {send Email to this account} > >But Received the following Error : > >rcpt to:finny.lee@yahoo.com.hk 550 5.7.1 Unable to relay > >I don't know what happen? You're using an anoymous SMTP session. Is your Receive Connector (assuming you're running Exchange 2007 or 2010) configured to allow anonymous sessions use it as an open relay? --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP

On Sun, 19 Feb 2012 09:24:34 +0000, Lee John wrote: > > >Dear all, > >I run the following command under the COMMAND PROMPT: > >telnet mycompany.com.hk 25 helo mycompany.com.hk mail from :aa@mycompany.com.hk {My company Email account} rcpt to:finny.lee@yahoo.com.hk {send Email to this account} > >But Received the following Error : > >rcpt to:finny.lee@yahoo.com.hk 550 5.7.1 Unable to relay > >I don't know what happen? You're using an anoymous SMTP session. Is your Receive Connector (assuming you're running Exchange 2007 or 2010) configured to allow anonymous sessions use it as an open relay? --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP

Hello, They are right. Please make sure if your clients IP is allowed to relay through exchange server and you specify anonymous users are allowed to connect to your receive connector. Here is the article on allowing application servers to relay off Exchange Server 2007. http://blogs.technet.com/b/exchange/archive/2006/12/28/3397620.aspx Best Regards, Lisa

Dear all, I run the following command under the COMMAND PROMPT: telnet mycompany.com.hk 25 helo mycompany.com.hk mail from :aa@mycompany.com.hk {My company Email account} rcpt to:finny.lee@yahoo.com.hk {send Email to this account} But Received the following Error : rcpt to:finny.lee@yahoo.com.hk 550 5.7.1 Unable to relay I don't know what happen? thank you john

Hi Are you running this on the Exchange server or from your desktop? The 550 5.7.1 means that it will not relay the message from the sending machine, which in this case would probably be your client. You need to have a receive connector that allows your client's IP to relay through Exchange. Cheers, Steve