I have an issue with Exchange server. My colleague can't send email to a specified address. We contact his mail provider and they replied that their system does not accept our mails because our mail host domain is not a public domain address.

They send the error message:

<svr2008.xxxxx.local>: Helo command rejected: Host not found

Where xxxxx.local is our local domain in the internal network. But this is not cause problem with other providers. How we could fix it? We need to set this value to our public domain where the MX records point to? (mail.xxxx.hu) If we need to set it, how we could set it?


This error is happening because the receiver server tries to check that the IP address of the sender server and the IP address of the HELO domain name that is sent with the mail are equal (SPAM servers like to fake the sender HELO name).

To set your FQDN name you need to do the steps below:

  1. Open Exchange Manager
  2. Select the Organization and Configuration from the left menu
  3. Then select Hub Transport
  4. On the Send Connectors tab click the active item(s).
  5. On the general tab edit your FQDN name to your domain which used by the MX records e.g. mail.yourdomain.com

These are the aliases of this error message:

  • Helo command rejected: Host not found;
  • Helo command rejected: need fully-qualified hostname;
  • Invalid HELO/EHLO:
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The remote host rejects your email because your .local Domain doesn't resolve to your IP address. I assume you don't have a fixed IP address and MX pointers set to that address or you would know about it. If you do then the other answer would apply.

So if you instead use a provider server to accept email for you (and then download that email to your Exchange via a POP3 connector) you also need to use the same provider to send out email. That way the outgoing IP will match your domain name MX records.

For that you need to configure the "smart host" (Exchange term for "provider SMTP relay server") in the Exchange send connector under Organisation Configuration > Hub Transport > Send Connectors to route all outgoing email via the smarthost/smtp relay of your provider. Don't forget to configure the username and password for that provider smtp relay. See https://www.servolutions.com/support/config_exchange_2010.htm#section2 for instructions and screenshots.

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  • This question was already answered. – NoNameProvided Jan 15 '14 at 12:47

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