fix mail error

src/model/mail.rs

@@ -128,10 +128,20 @@ Der Vorstand
                             .parse()
                             .unwrap());
                     let splitted = send_to.split(',');
+                    let send_mail = false;
                     for single_rec in splitted {
-                        email = email.bcc(single_rec.parse().unwrap());
+                        match single_rec.parse() {
+                            Ok(val) => {
+                                email = email.bcc(val);
+                                send_mail = true;
+                            }
+                            Err(_) => {
+                                println!("Error in mail: {single_rec}");
+                            }
+                        }
                     }
 
+                    if send_mail {
                         let email = email
                             .subject("ASKÖ Ruderverein Donau Linz | Vereinsgebühren")
                             .header(ContentType::TEXT_PLAIN)
@@ -152,4 +162,5 @@ Der Vorstand
                 }
             }
         }
+    }
 }