clicking on email link gets request to install outlook

[denno]

um...what I said....


Here's the problem as relayed to me in an email about a site I run:

When I click on the email link,
my computer wants me to
install MS Outlook;
when this person clicks on it,
apparently her computer
(or the link, - or ???) wants
her to use MSN.


In other words, these people cannot click on an email link in the site and thus send an email. I'm guessing it's something like their installed email programs (dunno what) need to be made the default. Or something. Anyone know just what this is actually?

Thanks