Smtp; 550 Access denied - Invalid HELO name (see RFC2821 4.1.1.1)

Question

I am running Windows Server 2008 R2, but I am getting smtp mail rejected from multiple domains.

To test this, I drop the text file into the C: \ inetpub \ mailroot \ Pickup directory, with something like this:

From: [e-mail] To: [e-mail] Subject: testing This is a test 

It will send to some domains, but some will return:

 Reporting-MTA: dns;DEDICAT-93I3U5A Received-From-MTA: dns;DEDICAT-93I3U5A Arrival-Date: Wed, 8 Aug 2012 12:50:58 +0100 Final-Recipient: rfc822; [e-mail] Action: failed Status: 5.5.0 Diagnostic-Code: smtp;550 Access denied - Invalid HELO name (See RFC2821 4.1.1.1) 

I understand that this may be related to configuring smtp on the server (IIS 7.5). Can someone give me advice on where to start?

Thanks,

Andy.

Answer 1

Some SMTP servers require that you send a valid host name using the HELO command, which also matches the return DNS address of the IP address from which the request is issued.

You can configure the host name that uses the IIS SMTP server through the old IIS6 management console. To do this, select the SMTP server, right-click and select Properties , go to the Delivery tab, and then click the Advanced button.

The reverse DNS for your IP address is usually controlled by your ISP.

Answer 2

FWIW, I had the same problem using hMailServer and setup instructions were found here . In the interest of other hMailServer users, you should specify a field here:

Answer 3

Here is the solution to the problem.

Set the Authorization property before creating the session, as shown below.

 properties.put("mail.smtp.auth", "true");