diff --git a/postman/src/sender.rs b/postman/src/sender.rs
index 08e83e9..096dad9 100644
--- a/postman/src/sender.rs
+++ b/postman/src/sender.rs
@@ -310,6 +310,7 @@ WHERE
             reminders
         WHERE
             reminders.`utc_time` <= NOW() AND
+            reminders.`channel_id` NOT NULL AND
             `status` = 'pending' AND
             (
                 reminders.`interval_seconds` IS NOT NULL