Outlook does not support recurring e-mail. Microsofts recommendation is to create a script that send the e-mail and to launch the script using Task Manager. Microsoft also provides instructions on how to e-mail a custome task for in a reoccurring fashion: http://support.microsoft.com/kb/239087
Below is a sample script from Microsoft Script Repository for sending an SMTP mail message from a .vbs script file.
Set objEmail = CreateObject("CDO.Message")
objEmail.From = "firstname.lastname@example.org"
objEmail.To = "email@example.com"
objEmail.Subject = "Atl-dc-01 down"
objEmail.Textbody = "Atl-dc-01 is no longer accessible over the network."
Make sure you have the SMTP service installed and use Task Manager to run this script.
Class: Information Worker: Outlook 2007 Power User*
Date: November 12, 2008
Location: Indiana State University
*The Information Worker series is available through LanTech Training in Indianapolis. Please visit their website for more information