I have a python GAE app that sends emails like in the example using the address of a registered administrator for the application as the “sender” address. When an email arrives from such an API call, here’s a pic of the attached warning.
This message may not have been sent by: EmergencyButtonApp@gmail.com
Learn more Report phishing
Am I doing something wrong? None of the 3 options mentioned in the “Learn More” link are relevant I believe: the sender is a gmail address so the “SPF and DKIM authentication” solution isn’t relevant, I’m not sending to a mailing list and I’m not using SMTP (I think, though maybe GAE is…).
Assuming you’re seeing this in production, it’s probably because you’re claiming to be from a gmail address, but sending via App Engine. Use one of your app’s email addresses as the sender (foo@yourapp.appspotmail.com) and it should work fine.