Fix send email request body

src/email_client.rs

@@ -32,8 +32,12 @@ impl EmailClient {
     ) -> Result<(), reqwest::Error> {
         let url = self.base_url.join("v1/email").unwrap();
         let request_body = SendEmailRequest {
-            from: self.sender.as_ref(),
-            to: vec![recipient.as_ref()],
+            from: EmailField {
+                email: self.sender.as_ref(),
+            },
+            to: vec![EmailField {
+                email: recipient.as_ref(),
+            }],
             subject,
             text: text_content,
             html: html_content,
@@ -56,13 +60,18 @@ impl EmailClient {
 
 #[derive(serde::Serialize)]
 struct SendEmailRequest<'a> {
-    from: &'a str,
-    to: Vec<&'a str>,
+    from: EmailField<'a>,
+    to: Vec<EmailField<'a>>,
     subject: &'a str,
     text: &'a str,
     html: &'a str,
 }
 
+#[derive(serde::Serialize)]
+struct EmailField<'a> {
+    email: &'a str,
+}
+
 #[cfg(test)]
 mod tests {
     use std::time::Duration;