Ticket link not opening

An email is sent soon after a ticket is created containing the url for the
ticket. Clicking on it doesn’t open up the page. Copying it into a browser
doesn’t work either.
Only when rt is accessed first through the web-site, does the whole link
work.
I’m using RT 2.1.88 with mod_perl support. Can anyone tell me why this is
happening?
Thanks in advance,
Parimala.