The following non-delivery report:
A problem occurred during the delivery of this message to this email address. Try sending this message again. If the problem continues, please contact your helpdesk.
means that the recipient mail system did not accept the message either beacuse of a temporary issue on any party's end or because the recipient email address was not found in the recipient system.
The Diagnostic information for administrators section may contain the following errors:
- #5.0.0 smtp; 500 Invalid recipient (#5.1.1)
- #5.0.0 smtp; 500 No such user here
- #4.0.0 smtp; ESMTP not accepting connections
- #554 5.7.1 Service unavailable; Client host blocked
- #550 5.4.6 RESOLVER.FWD.Loop; there is a forwarding loop configured in the directory
#5.0.0 smtp; 500 Invalid recipient (#5.1.1)
Both these errors are usually generated in cases of external delivery (from Intermedia mailbox to an external recipient). They indicate that either the spelling is wrong or the recipient mailbox no longer exist. You can check if that is the case by:
- using any public email address validator such as http://verify-email.org/, http://tools.email-checker.com/, http://www.verifyemailaddress.org/ etc.
- running telnet to the recipient mail server
To resolve this, contact the recipient directly with the result of your tests.
The error is usually generated when the sender's IP address is blacklisted. While it is the sender's responsibility to ensure their IP address doesn't get blacklisted, you can contact Support for IP address removal evaluation.
If the IP address, however, is blacklisted on other public blacklists, contact the sender so that they could request delisting.
#554 5.7.1 Service unavailable; Client host blocked
The error is usually generated when the sender's IP address is blacklisted on invaluementSIP or Spamhaus. To delist the IP address:
- ivaluementSIP - request the delisting from https://www.invaluement.com/removal/
- Spamhaus - request delisting from https://www.spamhaus.org/lookup/
Note: since Intermedia is not the owner of the sender's IP address, we can only work with our spam-filtering vendors and not any other blacklists.
Read the Knowledge Base article on There Is A Forwarding Loop Configured In The Directory Bounce Back for more information.