Add people I e-mail to the Safe Senders List
E-mail addresses that are listed in your Contacts are considered safe by the Junk E-mail Filter if the Also trust e-mail from my Contacts check box is selected (the default setting). However, you might also sometimes send e-mail to recipients who are not listed in your Contacts. Such recipient addresses are not considered safe by default. If you want these addresses to be considered safe, do the following:
1.On the Tools menu, click Options.
2.On the Preferences tab, under E-mail, click Junk E-mail.
3.Click the Safe Senders tab.
4.Select the Automatically add people I e-mail to the Safe Senders List check box.
This is quoted from Office 2007 Help files