Gmail Help

Gmail users can customize the 'From:' field of messages they send by adding all of their email addresses to Gmail. When a user requests to add another email address to send mail from, we send a verification message to the account the user wants to add. If you've received a verification message but didn't make the request, don't worry. No one can send mail using your email address unless you click the link in the message to verify that you'd like to add your address to the listed Gmail address.

Often times, users misspell their email addresses when entering multiple addresses to send mail from, so the confirmation message is delivered to the misspelled address instead of the user's address. You can simply delete the misaddressed mail to ensure that no one sends mail using your email address.