Mailto links still open Mail

The email handler is a separate macOS setting from the default browser. Setting Bouncer as your default browser does not change which app opens mailto links.

1. Open Settings > General.
2. Under Email Handler:, choose Bouncer.
3. Under Fallback Email:, choose the email client that opens when no rule matches. This row is dimmed until Bouncer is the email handler.

Mailto links now go to Bouncer first. Rules for email addresses and the fallback email client decide where each one opens. See Write a rule for email links.