RustMailer (a separate project) has a commercial license: https://github.com/rustmailer/rustmailer/blob/main/LICENSE

> RustMailer is source-available. The code is open on GitHub, but requires a valid commercial license key for production use.

License Purchase: https://rustmailer.com/pricing

The mention of BSD/Apache is from here[1] and looks to be a listing of open-source licenses that this project uses.

[1] https://github.com/rustmailer/rustmailer/blob/main/license.h...