I can receive mail, but I cannot send. This has happened recently, with no settings changed.

That is usually a sign of the ISP blocking SMTP.  They do this without warning, to try and control spam.  Please have him try the following:

Go to a command prompt, and run the following command:

telnet 25

The screen should go black, with a cursor at the top left.  Type HELO and hit enter, you should recieve a HELO back from the server.  Type quit and hit enter to exit the telnet.

If the client cannot get the helo response, they cannot connect to SMTP, and cannot send mail.  This means that either the ISP is blocking SMTP, or we are at the server due to past abuse.  To check if we are blocking, have the client go to, and let us know the IP address they are using.  We will check the block list.

In the case of an ISP block, you have the option of specifying our alternate SMTP port (587) in your outlook advanced settings which will allow your mail to be sent using our shared mail servers.

Article ID: 395, Created On: 9/25/2005, Modified: 5/26/2009

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