Today we open-source idn_generator – a tool that helps block recent homograph phishing attacks at the email stage.
The tool generates a list of similar domain names (IDN domains) for a given domain (usually the domain of an organization). You can feed this list to Google Apps/Office 365/Exchange and block those domains.
For more information check out the github page https://github.com/phishai/idn_generator and you can read more about the attack in the previous blog post.