diff --git a/src/main.rs b/src/main.rs
index 75e0d67..75cb407 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -99,7 +99,7 @@ fn main() {
 
     if args.message_id {
         builder = builder.header(MessageId::from(format!(
-            "{}@{}",
+            "<{}@{}>",
             uuid::Uuid::new_v4().to_string(),
             args.from_mail.rsplit_once('@').unwrap().1
         )));