Email Sender Image from Google+ Account

I'd like for all emails send from my server (e.g. mail@example.com) to arrive in recipients inboxes with a custom sender image used in Apple Mail and Google Inbox.

I have created a new Google+ account, linked and verified my website (by uploading the .html file, you know ;]), but still, the emails don't contain my Google + profile image as their sender image.

I assume it's something to do with me not sending emails from the new gmail address I've created with Google+. I'm hoping someone knows how to work around this and have Google+ treat any emails coming from my domain as the new Google+ account's own.

This Article seems to provide a good overall answer. I'll do a quick summary here.

As a takeaway:

• Ensure your site is verified on Google+. This is done in Webmaster tools(link), and your webmaster must approve.
• Ensure you have adequate email traffic (seems around 1k a week should do it).
• When sending from a domain not matching Google+, you'll need to include a snippet of code in your email, and have Gmail approve the link.
• Ensure that your email is authenticated against your domain and not your ESPs (or use the Featured Image markup).