XFOR: IMC Not Receiving Inbound Mail from UNIX Hosts (152944)



The information in this article applies to:

  • Microsoft Exchange Server 4.0

This article was previously published under Q152944

SYMPTOMS

After you apply Service Pack 2 to an Exchange Server running the Internet Mail Connector (IMC), connections from previously working SMTP hosts may fail with the following:
Event ID: 4051
Source: MSEXCHANGEIMC
Description:
A time-out occurred while trying to receive mail from <server> and while waiting for the message body.
The SMTP mail is not received by the Exchange IMC and mail destined for the IMC backs up in queues on the foreign mail system.

CAUSE

The Exchange IMC from Service Pack 2 expects a <CRLF>.<CRLF> to delineate the end of mail messages in accordance with RFC821, section 3.1. Prior to Service Pack 2 the Exchange IMC would accept a message terminated with <LF>.<LF>. This change in implementation of the RFC in Service Pack 2 affects many existing Exchange implementations.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. This problem was corrected in the latest Microsoft Exchange Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

WORKAROUND

Many SMTP mail hosts allow for the configuration of this "message termination sequence." Consult the specific SMTP mailer's documentation and configure the mailer to use <CRLF>.<CRLF> for this sequence.

Modification Type:MinorLast Reviewed:4/28/2005
Keywords:kbusage KB152944