Contact Groups can be used to send Email to multiple recipients, schedule meetings quickly with the same groups of people, and for other similar tasks.
To create a Custom Group go to Home > New Items > More Items > Contact Group
Figure 1: Contact Group command
Name the Contact Group, then select Add members
Figure 2: Contact Group
From Address Book
Figure 3: Add members drop down, select address book
Select the people you wish to add to the group from the Global Address List.
Figure 4: Select group members from address book
Click Members to add each person, Click OK when finished adding members.
Your members will now appear within the group.
In order to use the group start a new Email Message, click the To button. From within the Address Book drop down Menu select Contacts. Your Contacts Group (s) will appear.
Figure 5: Changing between contacts and global address list
When sending an Email message to all contacts your group will now appear and will contain all members of that group to be a recipient of an appropriately addressed email message.
Figure 6: New email to custom contact group