You can customise your emails with a gorgeous personalised background.
You can either have the email background shown for all transfers sent from your Plus Profile or exclusively for emails sent from your logged-in Plus account. Your avatar will only ever be shown when the transfer is sent from your logged in Plus account.
To set up your email background, go to the Profile page in your Plus account.
Click 'Upload background', this will open the finder on your device - now select the picture you will upload. Make sure to use a 1600 px wide image, with a height of 800 px.
Upload your background, and don't forget to save it. There it is, your awesome new email background!