The original post is from my blog Outlook-How-to.com. I am writing an Outlook add-in review series of "Save and Remove Outlook Attachments". Any comment is appreciated.

Microsoft Outlook is one of the most popular software in the world. However, Outlook should be one of the most seriously being complained software. The No.1 problem that people always complain is its speed. It usually takes half a minute to launch and we can do NOTHING in that period of time.
The huge .pst file that Outlook uses to store data is the main reason for its slow speed. I believe most people regularly send and receive attachments, Word and Excel files, Photo files and so on. Your Outlook .pst file can quickly increase to 200MB. After months, a single .pst file beyond 1GB is very common. So we should slim the .pst file. The most effective method is to save and remove attachments from emails.
First, find out the largest emails. Outlook 2007 has a very useful feature, "Larger Than 100KB". You can find it under Search Folders in your list of Outlook folders. All emails larger than 100KB will be listed in that folder. By default, the larger email will be listed first. Second, Check the emails and its attachments, save or remove the attachments. If you need the attachment but not the email message, save the attachment and delete the email. If you need the email message but not the attachment, open the email and right-click the attachment and choose Remove. The email will remain its message text only.
What a trouble and time-consuming procedure! There are tools to make it easy. Many third party solutions are created in the form of Outlook add-ins. They check all your emails, save attachments to disk, replace the attachments with shortcuts to stored attachment files. With the shortcuts, you can open the attachments as you do normally. The difference is that Outlook open the file from disk, rather than from its .pst file. The advantage is your .pst file increases in a very slow speed. This change dramatically speed up your Outlook.
A powerful Outlook attachment management add-in should have more features than the basic functions mentioned above. Attachment fils can be saved in either local disks or network disks. Email messages can be fully restored with attachments when it is forwarded to other recipients. Attachment fils can be renamed based on sender’s name, sender’s address, email subject and so on. Saving and removing attachment should have more flexibilities. For example, folders can be specified for add-ins to manage attachment. Attachment file types and size, sender and recipient, can be filterd by combinations of criteria.
Though free add-ins for Outlook attachment management are available. Commercial add-ins are recommended for the reasons of reliability and compatibility. Technical support is another factor for choosing add-in vendors.