When you start typing a contact's name in the To field of an email, Google autocompletes contacts and email addresses. You can remove a contact or email address you've added/used so that it does not appear as a suggestion in autocomplete. If you have an incorrect email address in your contacts or someone has changed email addresses, it's a good idea to delete the incorrect one.

1. Go to Google Contacts at www.google.com/contacts
2. Using the search bar at the top, search for the contact or email address you'd like to remove
3. Click on the contact you'd like to remove and the contact info will open
4. To delete the whole contact,
   1. Click the three-dot button and select Delete
      
5. To delete an email address (but not the whole contact)
   1. Click the pencil button
   2. Hold your mouse over the line you want to delete and click the X button; then click Save