Microsoft KB Archive/170471

From BetaArchive Wiki
< Microsoft KB Archive
Revision as of 16:35, 18 July 2020 by 3155ffGd (talk | contribs) (importing KB archive)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Knowledge Base

XCON: 290/4284 Errors Indicate Misconfigured MTA or Connector

Article ID: 170471

Article Last Modified on 10/28/2006


  • Microsoft Exchange Server 4.0 Standard Edition
  • Microsoft Exchange Server 5.0 Standard Edition
  • Microsoft Exchange Server 5.5 Standard Edition

This article was previously published under Q170471


The Microsoft Exchange Server Message Transfer Agent (MTA) may return messages back to originators with Non-Delivery Reports (NDRs) that state:

   Unable to deliver due to MTA congestion.

These NDRs will be accompanied by the following events logged in the Windows NT Server Event Viewer Application Log:

   4284 A error occurred during connection/disconnection.
   Error code: 8511 [POP4 POP4 DOWN 4 179] (14)

   290 A non-delivery report (reason code unable-to-transfer and diagnostic code
   maximum-time-expired) is being generated for message C=US;A= ;P=Organization;
   L=Server03-970224213600Z-1460. It was originally destined for
   DN:/o=organization/ou=sitename/cn=recipients/cn=recipientnameC=US;A= ;
   P=organization;O=sitename;S=user;G=joe; (recipient number 1); and was to be
   redirected to . [MTA DISP:RESULT 20 136] (12)


This combination of errors usually indicates a misconfigured MTA and/or connector. To troubleshoot this issue follow these steps:

  1. Verify that the Windows NT Servername matches the local MTA name.
  2. Verify that the naming conventions used to communicate between the two servers are functioning correctly.
  3. If X400 connectors are being used, make sure all the manually entered information is correct on both servers.

If any of these are incorrect, this behavior is by product design.

Keywords: kbinfo KB170471