If you already have sendmail installed edit /etc/mail/sendmail.mc Look for the line
DAEMON_OPTIONS(`Family=inet, Name=MTA-v4, Port=smtp, Addr=127.0.0.1')dnl
and edit like this
DAEMON_OPTIONS(`Family=inet, Name=MTA-v4, Port=smtp')dnl
Your VPS must be named host.myhomepage.com in manage.haphost.com, the first part **host** can be any hostname you like. This is the simplest configuration for sendmail and will only send/receive email for myhomepage.com or whatever domain name the command `hostname -d` returns. In your case it should be **myhomepage.com**
Also sendmail is only the MTA, you'll need to install and configure and MDA like dovecot or cyrus to be able to retrieve yor email via IMAP or POP3 protocols.
If sendmail is not installed you can have it installed with
sudo apt-get install sendmail
Enable the service
update-rc.d sendmail enable service sendmail start
From your home computer you can test its working using telnet or sending an email
telnet host.myhomepage.com 25 Trying 22.214.171.124... Connected to hostm.myhomepage.com. Escape character is '^]'. 220 hostm.myhomepage.com ESMTP Sendmail 8.14.4/8.14.4/Debian-4; ^] telnet> quit mail -s "TEst mail" email@example.com Hello sendmail .
And in your VPS logs you should see the conections details and the email arriving.
tail -f /var/log/mail.log
Congrats, now you can recive email, why don't go ahead and try to sending one out