Fallback to plain-text when STARTTLS is optional

tests/src/smtp/queue/dsn.rs

@@ -91,6 +91,7 @@ async fn generate_dsn() {
                 entity: "mx.domain.org".to_string(),
                 details: "Connection timeout".to_string(),
             })),
+            disable_tls: false,
             changed: false,
         }],
         flags: 0,

tests/src/smtp/queue/manager.rs

@@ -152,6 +152,7 @@ fn domain(domain: &str, retry: u64, notify: u64, expires: u64) -> Domain {
         notify: Schedule::later(Duration::from_secs(notify)),
         expires: Instant::now() + Duration::from_secs(expires),
         status: Status::Scheduled,
+        disable_tls: false,
         changed: false,
     }
 }

tests/src/smtp/queue/serialize.rs

@@ -79,6 +79,7 @@ async fn queue_serialize() {
                 notify: Schedule::now(),
                 expires: Instant::now() + Duration::from_secs(10),
                 status: Status::Scheduled,
+                disable_tls: false,
                 changed: false,
             },
             Domain {
@@ -87,6 +88,7 @@ async fn queue_serialize() {
                 notify: Schedule::now(),
                 expires: Instant::now() + Duration::from_secs(10),
                 status: Status::Scheduled,
+                disable_tls: false,
                 changed: false,
             },
         ],