Sent to contacts in my address book only

Hi,

I usually just type in the first name when I am sending a e-mail.
However, afer sending tons of e-mails there are a lot of "Jack" pop out when
I want to send to the only Jack in my address book.
Now I want to make my work e-mail back to the pure workplace.
Is there anyway I can limit all of my sending out e-mails to only the
contacts in my address book? I can add new business contacts into the book
when I need to send e-mails.

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