Configuring Your Exchange Server For Mail-On-Demand
To implement Microsoft Exchange Mail-On-Demand,
you will need to configure your Exchange Server to dial-up to the local
ISP on demand. How to do this should be documented in your Exchange Server manuals.
A great additional resource is provided by
essence you need to:
Configure your RAS/DUN
- You will need an entry in the phonebook that makes an automatic connection
to your local ISP at the intervals you specify.
- You need a TCPIP hostname and domain configured in Control
Configure the Exchange SMTP service
For Exchange Server 5.0 this will be the Internet
Mail Service. This should be pointed to the SMTP server for your Virtual
If necessary, configure the SMTP Addresses for your users
You can globally
configure this using the Site Addressing configuration page, or you can use
Directory Import to configure individual addresses. This would only be necessary
in the event you had multiple users in your "Intranet" that had a different
Configure the server to tell the mail server to dequeue mail
will need to configure your Exchange Server to run the "etrn" command. This
command tells the Virtual Server to attempt to resend your queued mail. The
dequeue.exe program, written
by Simpler Web Inc., will help set up your Exchange Server to do this.
In essence, you're connecting to your SMTP port and telling the mail server you
want to dequeue your mail. For those people not using Exchange Server, you could
write your own script. Here is an example Unix shell script that would do the
same (substitute your domain name for my-domain.com).
# I got this from:
# Send ETRN command to sendmail 8.8.x
# written by Andy Rabagliati <firstname.lastname@example.org>
telnet mail.my-domain.com smtp <<SMTP_EOF
# End of Shell script
echo "etrn $OURSITE" |$TELNET $MAILSERVER $PORT
You must have a dedicated IP address for the Exchange Server dial-up solution to work.
There is no other alternative to this (currently). You must do one of the following.
- Purchase a dedicated modem at your ISP's modem bank that only you connect to and
that is assigned your dedicated IP address
- Your ISP has the ability to detect when you dial in and can assign that dial-in your
dedicated IP number.
The second thing your ISP must do for you is map a domain name to that dedicated IP
address. For example, if your local Internet Service Provider has a domain name "my-isp.
com" and they were going to give you an IP address of 184.108.40.206, you want
them to map 220.127.116.11 to a unique instance of my-isp.com. As an example:
exchange.myisp.com mapped to 18.104.22.168
Here is an example DNS entry for this:
@ IN SOA ns1.my-isp.com. hostmaster.my-isp.com. (
1997072802 ; Serial number
86400 ; Refresh
7200 ; Retry
2592000 ; Expire
172800 ) ; Minimum TTL
MX 10 my-isp.com
exchange A 22.214.171.124
Another alternative would be to use your Virtual Server domain name in the zone file above
instead of the name "exchange". For example if I had a Virtual Server and my
domain name for the Virtual Server was mycompany.com
I might have my ISP set up their DNS zone to point to
mycompany A 126.96.36.199
Now, all mail sent to mycompany.my-isp.com would resolve to the dedicated IP
This is important, you must have a dedicated IP address (one that is uniquely assigned to
your Exchange Server), and you must have a domain name pointing to that IP address for
the Mail-On-Demand solution to work.
Virtual Server Configuration
Finally, you must Configure Your Virtual Server for Mail-On-Demand.