So instead, I adapted a short python script that sends email via the smtplib and email modules, and used Automator to run the script via an iCal plug-in (File>Save As Plugin). Creating a plugin creates an Automator calendar in iCal where your scheduled script resides. All you have to do is set the timing. I know the command-line folks probably use cron to schedule scripts like this, but I like seeing the scheduled script on my calendar. I also like the script approach because I don't have to launch any other applications (e.g., Mail). The script also works for those of you using google apps (just use your google apps email address).