Type the id in
Cc or. (Carbon copy)
Bcc. (Blind carbon copy)
When we select the typed email id in TO and press CTRL button and K button together the email id gets added in Microsoft Outlook's address book.
By this you are not required to type email ids again and again. By typing first letter options for full email id arrives. If you do not add this email ids in address book, everytime you have to do the hard work of typing same email id again and again. Means you have to type full. PC does not give you options.