You can quickly send an e-mail that will show your calendar availability. This can make it much easier to set up an appointment with another person.
You can create a rule that will drop a copy of an e-mail into a specific folder. This will allow you to keep track of the items you can not take action on until you receive a response. This Video is specific to Outlook 2010.
You can create a rule that will drop a copy of an e-mail into a specific folder. This will allow you to keep track of the items you can not take action on until you receive a response. This will work the same in Outlook 2003 and Outlook 2007.
Creating a column in e-mail folders to prioritize can be extremely helpful. This will allow you to print a to-do list of your top priorities. This video applies specifically to Outlook 2010. There is and additional video for Outlook 2003/2007.
Using the Auto Correct feature in Outlook can be a great time saving tool. It will allow you to create text shortcuts for phrases you use frequently when composing e-email messages.