To make it easier for users to find all of the security options available in Office applications, Microsoft grouped all security related options in the Trust Center. Each office application has a trust center with the options that apply to that application.
 
For all applications, the Trust Center has a list of your trusted publishers, lets you enable and disable add-ins and control macro security settings, and set privacy options such as using Office Online Help and Customer Experience Improvement program, and setting your reference and research options, including translation services. Additional options in the Trust Center are application specific.
 
Outlook's Trust Center contains the security related options that were previously spread between the Preferences tab (Email Options, Advanced Email Options) the Security tab, and Other tab (Advanced Options). This includes the automatic download options for embedded objects in HTML formatted messages, the email security options for configuring encryption and digital IDs along with read as plain text setting. You'll find Reply with changes in the Attachment Handling section, along with Attachment and Document preview, should you wish to disable attachment preview for all or some attachment types.
 
New to Outlook is the ability to disable or control the annoying alerts Outlook displays when a program is accessing your address book or sending email and you'll find these settings in the Programmatic Access section. While completely disabling this protection is possible, the default setting of disabling it when an up-to-date anti-virus scanner is installed offers the greatest protection with the least amount of hassle.
 
Look for the Trust center on the Tools menu.

In Exchange 2007 anonymous SMTP is disabled by default. The reason for this is Microsoft expects sites to use an edge server to collect the incoming mail pass it along to the mailbox server using a secured connection. While this is more secure and works well for larger sites with multiple servers, smaller sites with just one mail server will use Exchange 2007 in Hub role, acting as both an edge server and mailbox server. As a result, they will be unable to collect Internet email until they enable anonymous SMTP. Unfortunately, this setting is not exposed in the Exchange Management Console GUI, it needs to be configured using the Exchange Management Shell. It's easy to enable, but since it's not visible in the GUI, it may not be obvious to the administrator that anonymous SMTP is disabled.
 
The cmdlet that sets this is called Set-ReceiveConnector. If you are enabling it on the default receive connector, use the following command so you don't cut off access for those using other forms of authentication.
 
Set-ReceiveConnector "Default server_name" -PermissionGroups:"ExchangeUsers, ExchangeServers, ExchangeLegacyServers, AnonymousUsers"
 
You can learn more about the receive connector and the management shell at http://www.microsoft.com/technet/prodtechnol/exchange/E2k7Help/eb7f8960-e772-4312-9d3f-47dd27d9545c.mspx?mfr=true

Microsoft released an update to Office 2007 Beta 2 last week and it shows quite a bit of improvement. It seems to be faster in many areas, or maybe it's just my computer, I reformatted when the technical refresh refused to install and made the beta 2 installation inoperable.
 
 Among the changes you'll find, Instant search works better and Advanced Find uses the instant search index for some searches. RSS feeds work better and many of the problems with duplicates should be gone. The Send button was moved once again, this time to the left of the To, CC, and Subject fields. If multiple accounts are configured, the Accounts button is below the Send button.  While you'll probably hit the Paste button a few times before you get used to the new location, the button is visible at all times, regardless of which ribbon tab you’re currently using.
 
Potential problems, other than installation issues, include problems opening documents created in previous beta versions - it's recommended that you save your important documents in a legacy format before upgrading. You need to have beta 2 installed first and once the refresh is installed for any application, you will not be able to install other beta 2 applications, so install all beta 2 applications before upgrading to the refresh.
 
Download the Beta 2 Technical Refresh from http://www.microsoft.com/downloads/results.aspx?DisplayLang=en&nr=20&productId=4289AE77-4CBA-4A75-86F3-9FF96F68E491&freetext=2007officebeta2tr

What is contact linking? In previous versions of Outlook, most forms had a field on the lower right called Contacts which you could use to link a contact to an item which would then show up on the Activities tab. It was used most often to associate a contact with Calendar and Tasks items, since email is linked to the sender’s contact automatically.
 
Contact linking isn’t gone, it's just hidden away. To enable it, go to Tools, Options, Contacts Options button and add a check to the option under Contact linking to show it on most forms.