problem with mail()

I'm trying to send email from php and nothing happens. Sendmail is correctly setup in php.ini. When I checked the maillog file I see: ...: SYSERR(nobody): Can't create transcript file ./xfg7E9Jlr03988: Permission denied ....: SYSERR(nobody): Cannot create ./dfg7E9Jlr03988: Permission denied Does it mean that php is trying to send mail from user nobody? How do I set up nobody as mail user? Thanks