Here is a little bit on sendmail...

Contents:

I. Notes
   a. General Notes
   b. Running it through cil
II. Making a .cf file (shuddder...)
   a. Instructions on making a .cf file
   b. Necessary modifications (if you're not root)
III. Running the guy
   a. step by step on how to use this thing
IV. How to check if it worked


I. Notes

a. General Notes
Documentation:

sendmail/cf/README - information about making a cf file
sendmail/doc/op/op.txt or op.ps - users manual for sendmail
sendmail/README - release notes

There is also a lot of information about sendmail at www.sendmail.org. 
When you first download and uncompress sendmail, you must type in "sh Build" 
in the directory you extracted to in order to compile. It does not use "make" 
or anything yet on the first compilation. Once you type in "sh Build," it will
do its magic and under the "sendmail-XXX/obj-OSTYPE/sendmail/" directory you
will find the source files and the Makefile. It is from here that you can run
"make" and recompile sendmail. (Note: XXX is whatever version of sendmail you
downloaded, and OSTYPE is the operating system you are using, it is 
obj.Linux.2.4.5.i686 on manju). 

b. Running it through cil

This should be simple. In the cil directory, type in "make sendmail" on manju. 
If you have installed sendmail to a different directory, you must change the 
SENDMAILSRC definition in the Makefile.


II. Making a .cf file

a. Instructions on making a .cf file
Go to your sendmail/cf directory. From here, there are two subdirectories of 
note: cf and m4. Both of these contain files necessary to make your config
file. Here is the command to make a configuration file (run this from your
/sendmail/cf directory):

m4 ${CFDIR}/m4/cf.m4 config.mc > config.cf

CFDIR is the cf directory (/usr/local/src/sendmail-8.12.1/cf on manju)

config.mc is a generic name. You should replace it with the OS that you 
are running. Typically, I used generic-linux.mc.

config.cf is the name of the .cf file you want to make. config.cf or 
sendmail.cf are perfectly fine names.

Now, simply stick this file in the sendmail source code directory
(/usr/local/src/sendmail-8.12.1/obj.Linux.2.4.5.i686/sendmail on manju).

b. Necessary modifications
If you are not root, you will not be able to access the default mailbox
directory /etc/mail/ which is defined in the cfhead.m4 file, found in 
the m4 subdirectory. It is not recommended that you modify the .m4 files.
Instead, you can make modifications to a .mc file of your creation. I have
one named winston.mc found in the cf subdirectory. At the top, this line was
added: 

define(`MAIL_SETTINGS_DIR', `/home/winston/mailbox/')dnl

Note the difference between ` and ' used to quote the variable and definition.
This means that all mail will instead be deposited in subdirectories of
/home/winston/mailbox. For instance, mail will now be deposited in 
/home/winston/var/spool/mqueue.

Another thing you need to do is create a file called "local-host-names" in the
mailbox directory. So, just create a file called "local-host-names" and put
the name of the machine you are on. I put "manju@cs.berkeley.edu."

Lastly, you must make sure that port 9999 is available on the machine you are
working on (typically manju). You can check this by running the "netstat -anp"
command in Unix scrolling up to check what ports are in use. If it is not
available, you are going to have to modify the source code. Here's how to do it:

In daemon.c, change all occurrences of 9999 to some other port above 1024 that
is not in use.
In config.cf change all occurrences of 9999 to that same port above. Lastly,
change the TrustedUser to your manju login. (i.e. TrustedUser=winston, or
whatever your login is.)

III. Running the guy

Ok, now to the fun part. After running it through cil, you want to see if it
works. Here's the command to type in the $(SENDMAILDIR)/obj.Linux.xxx/sendmail
directory:

./sendmail -C config.cf -bD -v -d1

Of course, if you named your config.cf file differently, change that here.

The -bD flag tells it to run as a daemon in the foreground.
The -v flag tells it to go to verbose mode (it's not really necessary)
the -d1 flag tells it to go to debugging mode (not really necessary either)

Now you are running sendmail! Now, open another console. Type in 
"telnet localhost 9999" or whatever port you decided to use. If you are on
another machine, change the localhost to whatever machine you are running
sendmail on. You will get some sort of message telling you what you've 
connected. 

Now, type in: 
HELO blah
It's really not important what goes after HELO.

Now, type in the sender of this message. To do that, type in:
MAIL from: winston@manju.cs.berkeley.edu (or whatever address you are
sending from)

Next, designate the recipient. To do that, type in:
RCPT to: winston@madrone.cs.berkeley.edu (or whatever address you are
sending to)

Next, write the body. To do that, type in:
DATA (hit enter)
blah blah blah blah blah
Follow the instructions, end with a . on a line by itself.

Now, that's it. You've sent something! (hopefully). To exit, type in:
quit


IV. Checking that it worked

Now for the moment of truth. Go to one level above your mailbox directory (in 
the examples above, my mailbox directory was /home/winston/mailbox, so I would
go to /home/winston now) and go to the var/spool/mqueue directory. Inside there 
should be file with gibberish names on them. "cat" the ones starting with "dff."
One of those should be the body of your email. Wow, it worked! Sendmail just 
places the files here so the MTA can pick them up for delivery. That's it!