I have jst started using sendmail

["khalil KHAMLICHI" <khalil capinter com>]

I m new to linux world & all my previouse mail servers were ms exchange
servers. i jst installed a sendmail server & it seems to work fine after i
managed to tweak some config files ... now my last problem is how to allow
users who are using internet from thier homes or offices & who have accounts
on this mail server to use it to send mail bcos sendmail doesn't allow
relaying for them so far. from the documentation, i could see that sendmail
can be configured to relay by specifying the ip address of the trusted
networks or the domain but that jst doesn't work for me since i want them to
be able to send mail freely from whatever location the users were.
I will be very pleased with some help.
thanks in advance.