When composing a new email in Gmail, you can either start typing an email address and wait for the drop down list to show or you can use this tip.
Click on To in the corner of your email and a pop up box will open showing your Google Contacts list. You can search for contacts, or you can browse through your Contact Groups.
Once you have found the person you want to email, click on the name to add them to the To box. Multiple contacts can be added in this way – and there is an option to create an email Group for the people you email frequently.
Just search for the contacts you want to put into one group, select the box next to their name and when all your contacts are selected, click Save as Group.
This simple tip will save you time and prevent you missing anyone out.
You can use this to add Cc and Bcc contacts as well, simply click the Cc or Bcc text when composing an email.