Invoking sendmail with PHP

To recap, my problem is: I need some mailings sent immediately (confirmation emails, welcome emails, password lookup emails, etc), while others simply get thrown into the queue, and get sent the next time the queue processes. I contacted a sendmail guru, and he told me that if Sendmail is run with the -odb arguments, the mail will process immediately, while if it's run with the -odd arguments, it will only be queued. So the question is, using PHP, how do I invoke sendmail with the different arguments separately? __________________________________________________ Do You Yahoo!? HotJobs - Search Thousands of New Jobs http://www.hotjobs.com