Why can't I find this Harvard email using Manage People in Canvas?

When adding someone using the Manage Course / Manage People tool in Canvas, the only emails that the tool will recognize are people's official email address. A person can only have one official email address. This may be, and usually is, an email ending in harvard.edu. But it may not be. And a person may have more than one email address ending in harvard.edu. For example, aperson@gse.harvard.edu, aperson@g.harvard.edu, etc. 

If you find the email address you have is not working, as directed by the tool, please look the person up in the official Harvard directory: Connections. This will only list a person's official email and ought to be the one to use in the Manage Course / Manage People tool.