smtp;550 sorry, your HELO/EHLO greeting is not RFC2821 compliant (#5.7.1)

Posted on 2006-05-10
Medium Priority
Last Modified: 2008-01-09
I have installed Exchange Server 2003 on a computer. The Exchange server is working nice, but I got one error message when I try to send to one domain;
smtp;550 sorry, your HELO/EHLO greeting is not RFC2821 compliant (#5.7.1).

In System Manager I have tried to change the server to send HELO insted of EHLO (System Manager - Connectors - Small Bussiness SMTP Connector - Properties - Advanced - Send HELO insted of EHLO). The server has been restarted, but still I get the same error message. What can I do?
All other domains are working properly.
The server is a Small Business Server 2003 with all Service Packs and patches installed.
Question by:sigurdha
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LVL 18

Accepted Solution

amaheshwari earned 600 total points
ID: 16651625

You'll need to either make sure the windows server you're coming from is using a FQDN that resolves, or turn off helodnscheck in your mail server

Use http://www.dnsreport.com/ to test the domain name.

Part of the tests in the "mail section" (right under the MX section) is for "Mail server host name in greeting"

While you will only get a yellow (warning) if the greetings don't matcxh, many SPAM protection systems treat a mismatch as a forgery.

Thank you.
LVL 31

Expert Comment

ID: 16651936
Do you have any non-alphanumeric characters in your servername, besides periods?

Author Comment

ID: 16652389
Thanks for quick reply!
Amaheshwari: Since we want to wash our e-mail for spam and viruses before it reach the server, the MX record for the domain is pointing to a ISP. The ISP will forward the e-mail to our server when the scanning process is completed. Therefore I get answer from the ISP email server when I check the domain... Do you know other tools I can use to check this, where I can use IP adress?
LeeDerbyshire: The servername is: xxxxx-xxx.

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LVL 104

Assisted Solution

Sembee earned 300 total points
ID: 16653071
This problem is down to what the server is announcing itself as.
You need to ensure that is a valid name, that resolves on the internet.

ESM, Servers, <your server>, Protocols, SMTP. Right click on the SMTP VS and choose Properties. Click on the tab "Delivery" and then "Advanced". In the box labelled DNS enter what the server is known as on the internet....


There should be no invalid characters in the name - such as underscores.
The name needs to be resolvable, so get your domain name registrar to configure the host for you. Ideally you should also get the reverse DNS setup by your ISP as well.

LVL 31

Expert Comment

ID: 16653485
Since your MX records are pointing to your ISP, do you know if your outgoing messages are also being relayed through your ISP?  Do you have them configured as your smart host?  The problem might be with your ISPs server name - although you would expect them to know about things like this.

Expert Comment

ID: 16656708
RFC2821  means reverse lookup issue

550 Sender Domain must exist


550-EarthLink does not recognize your computer ( as connecting from an EarthLink connection


If you do not have a good DNS server locally use a external one from the isp and create a Smart host.



Author Comment

ID: 16697880
Doh... I changed the FQDN from domain.com to mail.domain.com. domain.com point to my ISP, and mail.domain.com point to the server...
Thanks for all help!!! Great!
LVL 18

Expert Comment

ID: 16697984
Great to listen that everything is fine now.

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