What is White Listing ? How do I white list an email ?
Whitelist: The whitelist is a list of (legitimate) email addresses that you always wish to see in your INBOX. Each address should be entered on a separate line.
How to White List: Followig steps are for Horde web mail interface. Other web mail interfaces are similar to this one.
1. Login to your web mail control panel at http://yourdomain.com/webmail
2. Click on Filters on left
3. Click on Whitelist link on top
4. Enter the email address you want to add into your whitelist and click Save

