Outlook contacts should utilize drag n' drop.

[Damen Gilland]

When you create a new message you should be able to select any number of
contacts and simply drop them into the message "to" "cc" or "bcc" fields.
Also, when you create a new Contact Group you should just be able to drag new
members into it (both when it's open and when it's just sitting in the
folder).

 

[Brian Tillman]

When you create a new message you should be able to select any number
of contacts and simply drop them into the message "to" "cc" or "bcc"
fields.

It works that way for me.