integration-test: fixup a test flake

crates/integration-tests/src/test/tsa_campaign_suspension.rs

@@ -1,6 +1,6 @@
 use crate::kumod::{DaemonWithTsa, MailGenParams};
 use kumo_api_types::SuspendV1ListEntry;
-use kumo_log_types::RecordType::{Delivery, TransientFailure};
+use kumo_log_types::RecordType::{Delivery, Rejection, TransientFailure};
 use std::time::Duration;
 
 #[tokio::test]
@@ -30,6 +30,14 @@ async fn tsa_campaign_suspension() -> anyhow::Result<()> {
         )
         .await;
 
+    daemon
+        .with_maildir
+        .wait_for_sink_summary(
+            |summary| summary.get(&Rejection).copied().unwrap_or(0) > 1,
+            Duration::from_secs(50),
+        )
+        .await;
+
     let delivery_summary = daemon.with_maildir.dump_logs().await?;
     k9::snapshot!(
         delivery_summary,