Newbie Sendmail Question

[dps]

I have somewhat of an easy question regarding sendmail.  I'm sure the
solution is easy, but I just can't seem to figure out what is going on.

First off, I want to say that I have sendmail installed, and it works
properly.  I can send and recieve e-mail from the box no problem.

Basically, my problem has to do with outgoing mail... When I send outgoing
mail, it shows up as being from "User LOGIN" and the host is
"dps.sockthief.com".  dps.sockthief.com is the hostname returned when typing
"hostname" from the command prompt.

Here is a partial listing for my zone file for named:

$TTL 3600
@                       SOA     ns.sockthief.com. dps.sockthief.com.   (
                                2004041203
                                3600
                                7200
                                604800
                                86400
                                )
                        NS      ns.sockthief.com.
                        NS      ns2.sockthief.com.
                        MX      10 mail.sockthief.com.
                        A       65.75.178.150
ns                      A       65.75.178.150
dps                     A       65.75.178.150
mail                    A       65.75.178.150

Also, here is:

dps# cat /etc/mail/local-host-names
sockthief.com
mail.sockthief.com

As you can see, sockthief.com, dps.sockthief.com, mail.sockthief.com are all
bound to the same IP.  So basically, my questions are this:

1) When I send outgoing mail, how do I get the source address to appear as
just sockthief.com as opposed to dps.sockthief.com?

2) My user name when i login is "dps" in just all lowercase, but for some
reason, on the inbox of the person I'm sending mail to, it shows up as being
from "User DPS".  Is there a way to change this on a global basis?

Sorry if I am was unclear, I'm not used to posting to this list yet.
Hopefully I gave enough information, however if you have any more questions
or need clarification, feel free to write me back. Cheers!

~Dan