Article ID: 300171 - View products that this article applies to.
This article was previously published under Q300171
This article is a consolidation of the following previously available articles: 322358, 840468 and 924235
When you try to send or receive messages on a computer that is running Microsoft Exchange Server 2003, Microsoft Exchange 2000 Server, or MIcrosoft Windows Small Business Server 2003, you experience one of the following symptoms:
The sender may receive the following non-delivery report (NDR) that contains the 5.5.0 error code. This code indicates a generic SMTP failure.
Note You may also receive the following error code: #5.5.4 Transaction failed.
> Your message did not reach some or all of the intended recipients. > > Subject: > Sent: 5/24/01 6:41 PM > > The following recipient(s) could not be reached: > > email@example.com on 5/24/01 6:41 PM > Your mail system could not find a way to successfully communicate with the destination system. Please notify your administrator. <Server.source.com> #5.5.0
Additionally, the Windows Event viewer on the Exchange server that is sending the message may contain an event 4000 or an event 4001 that is similar to the following:
Event Type: Warning
Typically, this problem occurs if the destination SMTP server performs a reverse lookup and if one of the following conditions is true:
Note If your Network adapter that is connected to the Internet is using a dynamic IP address, you may have to configure Exchange Server to route mail from the source.com domain through an SMTP connector to a smart host.
Note You can configure the Exchange server to reject incoming connections by specifying a domain name on the SMTP virtual server. When this is done, reverse lookups are performed on all connection attempts. This setting is available under Connection Control on the Access tab when you right-click the SMTP virtual server and then click Properties.
To resolve this problem, follow these steps:
Reverse Lookup causes additional overhead on servers, but is commonly used to help prevent environments from getting unsolicited e-mail messages (spam). You can configure your SMTP server to perform reverse lookups on incoming e-mail messages. This makes sure that the IP address and the fully qualified domain name (FQDN) of the sender's e-mail message server match the sender's domain name.
The mail servers of some Internet domains require that you create a valid PTR record that points the sending server's IP address to the local SMTP domain namespace. Sometimes these mail servers require that the PTR record match the actual FQDN of their SMTP Virtual Server on Exchange. Typically, this is the MX record. These Internet domains include AOL.com, Qwest.net, Mindspring, Earthlink, and Outlook.com. To send mail to these domains, create a valid PTR or a reverse lookup record on your company’s external or Internet DNS server.
If you telnet to the destination server's SMTP port and then attempt an SMTP conversation, the conversation will look similar to the following:
Additionally, if you telnet to port 25 on one of the AOL MX records, the following appears:
C:\telnet server.destination.com 25 220 mail.destination.com ESMTP Postfix helo source.com 250 mail.destination.com mail from:firstname.lastname@example.org 250 Ok rcpt to:email@example.com 554 <firstname.lastname@example.org>: Sender address rejected: Domain not found
220-rly-ya06.mx.aol.com ESMTP mail_relay_in-ya6.3; Fri, 20 Jan 2006 22:15:42 -05 00 220-America Online (AOL) and its affiliated companies do not 220- authorize the use of its proprietary computers and computer 220- networks to accept, transmit, or distribute unsolicited bulk 220- e-mail sent from the internet. Effective immediately: AOL 220- may no longer accept connections from IP addresses which 220 have no reverse-DNS (PTR record) assigned.
For more information about reverse DNS lookup for incoming messages, click the following article number to view the article in the Microsoft Knowledge Base:
297412For more information about PTR records, click the following article numbers to view the articles in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/297412/ )The "Perform Reverse DNS Lookup for Incoming Messages" option is for host name resolution
(https://support.microsoft.com/kb/166753/ )Microsoft DNS server reverse lookup error adding host record
322856For more information about DNS and about reverse lookup zones, visit the following Microsoft Web site:
(https://support.microsoft.com/kb/322856/ )How to configure DNS to use with Exchange Server
For more information about configuring an SMTP connector in Exchange 2000 and Exchange Server 2003, click the following article number to view the article in the Microsoft Knowledge Base:
265293For more information about how to use port 25 to test SMTP communication, click the following article number to view the article in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/265293/ )How to configure the SMTP connector in Exchange
153119For more information about similar problems in Microsoft Exchange Server 5.5, click the following article number to view the article in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/153119/ )Telnet to port 25 to test SMTP communication
(https://support.microsoft.com/kb/198981/ )SMTP messages not being delivered to certain domains
Article ID: 300171 - Last Review: September 12, 2013 - Revision: 6.0