1. For a photo stored in your Google+ account or in Google Photos, click Get link on your photo.
2. Click on the link next to COPY
3. Click on your photo to bring it to full screen.
4. Right click then choose "Copy Image Address."
4. Copy and paste to your email template, then click OK
NB: Do not copy and paste the URL in your browser as this will only copy the link to where your photo is stored, not the image itself.
Your photo is now ready to be emailed!