sendmail /etc/mail/Makefile usage

[JJB]

Looking for explanation documentation on the customization process
of FBSD's sendmail.

The /etc/mail/README talks about using the
m4 command to customize sendmail. I have all ready been told that
process is incorrect for the built in version of sendmail as
delivered by the FBSD install.

Previous posters to my sendmail questions said to read the
/etc/mail/Makefile which I have.
It does not explain the overall process either.
It just gives some hints.

I am only interested in 2 things, have sendmail use
'fbsdjones.com' as the local domain and tell sendmail not to
do reverse DNS lookups.

I have /etc/rc.conf  hostname='gateway.fbsdjones.com'   for the
gateway/firewall/sendmail PC which is the doorway to my private Lan.

The other FBSD PCs on the Lan have hostnames= of  tom.fbsdjones.com,
bob.fbsdjones.com, dad.fbsdjones.com, and mom.fbsdjones.com.

I am not running an DNS server and don't want to for
this very small Lan.

The gateway  /etc/hosts file has this

::1			localhost localhost.my.domain myname.my.domain
127.0.0.1		gateway   gateway.fbsdjones.com   fbsdjones.com

#          fbsdjones.com Private IP address network.
10.0.10.2		Landad   dad.fbsdjones.com
10.0.10.3		Lanmom   mom.fbsdjones.com
10.0.10.4		Lantom   tom.fbsdjones.com
10.0.10.5		Lanbob   bob.fbsdjones.com

When I use the 'mail' command to send mail it creates the senders
email as dad at gateway.fbsdjones.com. It should be dad at fbsdjones.com.
If I am on the dad.fbsdjones.com Lan PC and use mail command the
senders email address is dad at dad.fbsdjones.com.
Same thing for the other Lan PCs.

Do I have to change all the hostname= statements to
hostname=fbsdjones.com to get all the separate PCs aligned to
use the same domain name?

Or do I have to customize sendmail on all PCs to use fbsdjones.com
as domain name and not the hostname=value name?

Is there an way to customize the client program called 'mail' so it
knows the correct domain name to use for the sender?

Is there an better mail client program that is delivered as part of
the basic install? I all ready know there are better ones in
the port system.

Previous posters said in reply to my question about
'telling sendmail not to do reverse DNS lookups', that I need
an /etc/mail/service.switch file which I have to create new.

So what is the single statement I have to put in this file to tell
sendmail to stop doing reverse DNS lookups?

Do I have to do anything special to this file to activate it?

Thanks in advance.