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Don Rhummy
Asked: 2011-12-02 18:00:55 +0800 CST

Can't get past "HELO" command with my Exchange Server despite setting Receive Connector to trust it?

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I set my Exchange server to trust my IP address as specified here: https://serverfault.com/a/207583/101328 (Allows my ip, no authentication, set to "Externally Secure")

However, it still does not work! The following occurs:

Server: 220 server.mydomain.com Microsoft ESMTP MAIL Service ready at Thu, 1 Dec 2011 19:26:23 -0500

//This actually has my ip address, not x's
MyClient: HELO [xxx.xxx.xxx.xxx]

And then my client just hangs forever. Any idea what's wrong and what I can do to fix this?

I'm connecting to the exchange server on port 25.

exchange smtp exchange-2010

2 Answers

  1. Best Answer

    Are you coding your own client? If so, it's likely because you're not complying with section 2.3.7 of RFC 2821:

    Lines consist of zero or more data characters terminated by the sequence ASCII character "CR" (hex value 0D) followed immediately by ASCII character "LF" (hex value 0A). ... Conforming implementations MUST NOT recognize or generate any other character or character sequence as a line terminator.

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  2. Things to Try:

    1) Stop and restart the SMTP connector. If you configured the exception without restarting this, then chances are the changes will not take affect.

    2) From a telnet client like Putty or from the command line Telnet client try passing a SMTP conversation to it - first from the server, then on the PC your client is running on. I recommend creating a text file using the example in this wiki as a guide: http://en.wikipedia.org/wiki/Smtp Scroll down to the "SMTP Transport Example" section.

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