[plug] Sendmail Is it possible to spool mail locally

[James Robert New]

I have four users that have email accounts that are used through my computer on
their respective accounts. ie user1 at iprimus.com.au, user2 at iprimus.com.au and so
on.
 Using Fetchmail has eased the receiving  bit but being curious I would like
to give Sendmail a go.
I would like to have the clients send to sendmail and then have the system
deliver the mail to my ISP's SMTP when  I connect to the ISP.
The idea is to avoid dial on demand, by storing the mail on the system
somewhere till I do connect then have  automated mail sending.
I feel that sendmail can do this.
I have been reading Sendmail for Linux by Rich Blum but it seems to land on
either side of my requirement and I have been unable to bridge the gap.
So I would really appreciate  a point in the right direction.

I hope I have supplied enough detail about my problem.

TIA 
(Thanks In Advance)
James