sendmail vs smpt

Hi all. I'm curious as to the performance difference between scripts that use sendmail vs. smtp for their mailing abilities. I use the following class for delivering emails, http://phpmailer.sourceforge.net <http://phpmailer.sourceforge.net/> , and since I don't have sendmail running on my local machine I'm using the smtp server of the university where I work to deliver my messages. However, it seems to be a bit sluggish. I'm going to run a test of switching the mail handler from smtp to sendmail once the application is in its permanent home in a few weeks, but for now does anyone have any opinions on this, and is there any advantage to using one over the other? Thanks in advance, Pablo