- Sendmail
A mail server the above sendmail.org offers information about setting
up and using sendmail - actually too much information. It is often so
complete that navigating your way through the information to know what
you should do seems impossible.
The following is a simple method of setting up sendmail, on your
server, and then testing that everything
is as it should be. It does not take into consideration everyone
special needs; it is simple and yet should
do well for most servers.
Setting up sendmail:
1. First off you need a simple way of
configuring and maintaining sendmail -
you need to get Webmin. Here is a page that shows you how to get it
and how
to set it up (15 minutes work, it's worth it).
2. Start using Webmin to configure
your sendmail daemon by accessing it
through your web-browser:
http://yourserver.com:10000/
a)Click the tab for servers and
then click on the Sendmail configuration.
b)For now we are just going to stop
the sendmail daemon - we will do more
here later. At the bottom of the sendmail
server screen click on "Stop Sendmail".
You can minimize your webbrowser window we
will use it again in a minute.
3)Now telnet into your server and
login as root - this may require you to login
as an ordinary user and the do a switch user
to root as so:
su - root
4. Before SPAM control can work you
need to modify your sendmail.mc file and
generate a new sendmail.cf file.
As root, edit the /etc/mail/sendmail.mc file by
commenting out (have the line begin
with dnl) the line high
lighted below.
dnl This changes sendmail
to only listen on the loopback device 127.0.0.1
dnl and not on any other
network devices. Comment this out if you want
dnl to accept email over the network.
dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1,
Name=MTA')
dnl NOTE: binding both IPv4 and IPv6 daemon to the
same port requires
dnl a kernel
patch
dnl DAEMON_OPTIONS(`port=smtp,Addr=::1, Name=MTA-v6,
Family=inet6')
dnl We strongly recommend to comment
this one out if you want to protect
dnl yourself from spam. However, the
laptop and users on computers that do
dnl not have 24x7 DNS do need this.
dnl
FEATURE(`accept_unresolvable_domains')dnl
Now we need to generate a new sendmail.cf
file, as root issue the as follows:
m4 /etc/mail/sendmail.mc >
/etc/sendmail.cf
5. You can now reopen your
web-browser and your Webmin program, we opened
earlier. We have a few sendmail
administrative tasks... you should start by checking
out your Local Domains control screen -
mine look like this...
and your SPAM Control screen:
Make sure you set yours appropriately, for your server...
Here is how I allowed RELAY for my domain:
6. You can now restart the sendmail
daemon - using your web-browser and your Webmin program. At the bottom
of the sendmail server screen click on "Start Sendmail"
7. You should always test your site
to make sure it can't be used for SPAM
relaying - you can test your system, by using
telnet to relay-test.mail-abuse.org.
This will only test the system which connects
to it and determine if you are an
open relay site (allowing SPAM to run through
your site). If you fail this test
shut your sendmail down and fix the
problem. Use the sites listed below to
learn more about SPAM prevention and testing.
Anti-Spam, Mail relay
- Sendmail.org:
Anti-Spam Configuration Control
-
 Mail relay testing
- test THIS HOST for
mail relay NOW
- MAPS
TSI: Anti-Relay: Is My Mailer Vulnerable?
- Mail Abuse Prevention
System
- ORBS
- IMRSS (Open Mail
Relays)
- Fight Spam on the
Internet!
- UCE
(Spam) Control Measures at WebTV Networks
-
|