From the Category Menu on the left select "Mail & Groups". If there is a "+" to the left of it, click on it so it becomes a "-" and the "Mail & Groups" menu is expanded.

Click on "Identity". Your settings on the right side should then be as follows:

Your name:
Should be your name, for example, Joe Smith.

E-mail Address:
Should be your e-mail address.

Reply-to-address
Can be blank.

Organization:
Can be blank.

Signature File:
Can be blank.

Click on "Mail Servers" on the left.

Proceed to Step 3.