feat: update mailsend

__network/mailsend/src/main.rs

@@ -2,7 +2,8 @@ use mail_send::mail_builder::MessageBuilder;
 use mail_send::Transport;
 
 // https://github.com/stalwartlabs/mail-send
-fn main() {
+#[tokio::main]
+async fn main() {
     // Build a simple multipart message
     let message = MessageBuilder::new()
         .from(("John Doe", "john@example.com"))