Email alerts are not sent frequently. Unless there is nothing to report on you should receive one a month. If that. Email alerts are sent as plain text emails.

Disclaimer

Rest assured that your email address will not be sold, given away or shared with anyone, but only used to send you email alerts from this site.

Also, Chrome OS Email Alerts are not official communications from Google but a tool to notify people of new content on this (unofficial) guide.

You you don't like to receive email alerts you can subscribe to the RSS feed instead.