Set up recipient information directly from the Create screen
Since most people these days have multiple email addresses, say one for work and one for personal use, Gmail probably has more than one stored for many of your contacts. As a result, Gmail can autofill the field To who † CC or BCC by entering the wrong entry when you start typing your email recipient’s name. However, Gmail makes editing this information quite easy right out of the box. A new message †
If you want to change or edit a recipient’s email address when you write a new email or reply, you don’t need to delete the recipient completely or enter it manually. Instead of:
Double click on the recipient whose address or name you want to change.
Make any necessary changes to the recipient’s name or address. If you enter multiple letters in the field To who † CC or BCC , Gmail displays the appropriate options in the drop-down menu. Select the correct address from the menu or continue entering the address manually.
Select Enter †
If you suspect you have clicked Enter with an invalid address, you may be able to unsend in Gmail if you act quickly.