XCON: IMS Queues Back Up to Hosts with Multiple MX Records (152165)
The information in this article applies to:
- Microsoft Exchange Server 5.0
This article was previously published under Q152165 SYMPTOMS
If you are running Microsoft Exchange Server 5.0 with the Internet Mail
Service (IMS) installed, your server may experience slow delivery to hosts
that have multiple MX records of equal weight. Internet hosts supporting
multiple IP addresses are often the same hosts receiving high volumes of
mail.
CAUSE
When host addresses are resolved by Domain Name Service (DNS), a list of
records is returned if the site has multiple MX records defined. The IMS
attempts to randomize its choice of the available MX records. This is done
to spread the load evenly over the sites' MX hosts. The randomization code
is behaves poorly for sites with more than a few MX records of equal
weight.
STATUS
Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 5.0.
This problem was corrected in the latest Microsoft Exchange 5.0 Server U.S.
Service Pack. For information on obtaining the service pack, query on the
following word in the Microsoft Knowledge Base (without the spaces):
| Modification Type: | Minor | Last Reviewed: | 4/28/2005 |
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| Keywords: | kbusage KB152165 |
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