wierd sendmail/mail problems

Hi all, am baffled...I've got a function to email a message that works perfectly as a simple function. I've written it 2 ways, (1) using mail and (2) writing the message to a tempfile and then sending the tempfile to sendmail both ways work. Now here's the problem...when I incorporate this function into a page that gets input from an html form, creates sessions, checks for errors, says thank you and then emails the responses it fails. Here are the errors I'm getting for the 2 different approaches: Warning: error: mail(): Could not execute mail delivery program Warning: system(): Unable to fork [/usr/lib/sendmail -t < /var/tmp/FOOVFaqq2] any clues to what I'm doing wrong? thanks in advance, Pam