link: https://gist.github.com/irazasyed/a5ca450f1b1b8a01e092b74866e9b2f1 tags:

• email
• Cloudflare
• Gmail
• SPF
• DMARC

The key part of this is that you need to add your routed email address as a new account in gmail, uncheck "treat as an alias", and then use a Gmail app password in the "send as" details for SMTP.

Create a new app password here

Finally, you need to modify the SPF record to include Google:

v=spf1 include:_spf.mx.cloudflare.net include:_spf.google.com ~all

And set a DMARC record:

v=DMARC1; p=none; rua=mailto:<your-email-to-report>