diff --git a/lib/Listener/OptionalIndicesListener.php b/lib/Listener/OptionalIndicesListener.php
index 40046dc267..821912c252 100644
--- a/lib/Listener/OptionalIndicesListener.php
+++ b/lib/Listener/OptionalIndicesListener.php
@@ -60,6 +60,12 @@ public function handle(Event $event): void {
 			['mailbox_id', 'flag_deleted', 'sent_at'],
 		);
 
+		$event->addMissingIndex(
+			'mail_messages',
+			'mail_msg_imip_idx',
+			['imip_message', 'sent_at'],
+		);
+
 		$event->addMissingIndex(
 			'mail_classifiers',
 			'mail_class_creat_idx',
diff --git a/lib/Migration/Version1130Date20220412111833.php b/lib/Migration/Version1130Date20220412111833.php
index 69b6070f09..b2a830f874 100644
--- a/lib/Migration/Version1130Date20220412111833.php
+++ b/lib/Migration/Version1130Date20220412111833.php
@@ -176,6 +176,9 @@ public function changeSchema(IOutput $output, Closure $schemaClosure, array $opt
 		// mail_msg_mb_del_snt_idx was added later and may not exist until optional indices are created
 		$messagesTable->addIndex(['mailbox_id', 'flag_deleted', 'sent_at'], 'mail_msg_mb_del_snt_idx');
 
+		// mail_msg_imip_idx was added later and may not exist until optional indices are created
+		$messagesTable->addIndex(['imip_message', 'sent_at'], 'mail_msg_imip_idx');
+
 		return $schema;
 	}
 
diff --git a/tests/Unit/Listener/OptionalIndicesListenerTest.php b/tests/Unit/Listener/OptionalIndicesListenerTest.php
index 0ee6931a67..dc650e1ded 100644
--- a/tests/Unit/Listener/OptionalIndicesListenerTest.php
+++ b/tests/Unit/Listener/OptionalIndicesListenerTest.php
@@ -52,5 +52,6 @@ public function testHandleRegistersOptionalIndices(): void {
 
 		$indexNames = array_column($event->getMissingIndices(), 'indexName');
 		self::assertContains('mail_msg_mb_del_snt_idx', $indexNames);
+		self::assertContains('mail_msg_imip_idx', $indexNames);
 	}
 }