I'm opening this issue because I ran into some trouble with manual testing. When I went to test my template changes against the API, using the skipped test, I have been hitting snags with sending any sort of request to the Postmark API.
The manual test in this branch can be run with cargo test --test send_email. I made the test match what is in the package docstrings pretty closely.
thread 'send_email' panicked at 'called `Result::unwrap()` on an `Err` value: Client { source: Communication { source: reqwest::Error { kind: Request, url: Url { scheme: "https", cannot_be_a_base: false, username: "", password: None, host: Some(Domain("api.postmarkapp.com")), port: None, path: "/email", query: None, fragment: None }, source: hyper::Error(Connect, "invalid URL, scheme is not http") } } }', tests/send_email.rs:37:10
This error will throw when the scheme is https. I'm not sure what is going on in the middle with reqwest and why it is expecting http, but it should pretty clearly be https to communicate with Postmark.