When resolving names for non-local message delivery, SMTP
virtual servers will query all DNS servers
configured in Windows 2000 for all network interfaces. If your
Exchange server has interfaces on both internal and external
(Internet) networks, the potential mix of internal and external DNS
servers is not recommended. An external DNS server could be queried
to resolve an internal host name, for example; if this happens,
e-mail flow within your organization could be affected by DNS
servers outside your intranet. You can, however, create a list of
external DNS servers for resolving names in remote domains.
Whenever a message intended for a non-local recipient is received,
the SMTP virtual server will automatically consult this list.
Note After the external DNS
server list is created, the SMTP virtual server only uses the
servers on that list. If you want to keep using some or all of your
local DNS servers, you need to manually add those IP addresses to
the list.
Right-click the SMTP virtual server, and then click
Properties.
On the Delivery tab, click Advanced.
In Advanced Delivery, click Configure.
In Configure, click Add, type the IP address of a
DNS server, and then click OK. Repeat this step for every
server you want to add to the external DNS list.
Highlight a server in the list, and then click Move Up
and Move Down as necessary to set the order. The SMTP
virtual server will start with the top DNS server and descend the
list until one of the servers returns the information it
needs.
Note To remove a server from
the list, highlight it, and then click Remove.