Every integration has a Send Test button that fires a synthetic incident payload to the channel and confirms delivery in the UI.
Open the channel row in Settings → Integrations and click Send Test. Lemwatch fires a synthetic incident payload and displays delivery status inline. A green tick means the provider accepted the message.
Settings → Integrations → <channel> → Send Test.
Check alert rules: the channel may not be routed to the specific site or severity.
No — synthetic tests are free.