Alert coverage

Not every alert source reaches every channel type. A channel of a type the source does not support is skipped: no alert arrives on it, and a skipped receipt records why (see Skipped deliveries). Saving the monitor still succeeds, with a warning. Keep an email or SMS channel in every group that has to page someone.

Monitor and rule alerts

Alert source	Reaches	Skipped
HTTP monitors, browser checks, domain expiry, log/metric/trace alert rules and RUM issues	All 13 channel types	None
Heartbeat (cron) monitors	Email, SMS, Slack, Webhook, Telegram, PagerDuty	Discord, Microsoft Teams, Opsgenie, Google Chat, Mattermost, Pushover, Pushbullet
TLS certificate expiry and page speed	Email, SMS, Slack, Webhook, Telegram, Discord, Microsoft Teams	PagerDuty, Opsgenie, Google Chat, Mattermost, Pushover, Pushbullet
DNS record changes	Email, Webhook, PagerDuty	SMS, Slack, Telegram, Discord, Microsoft Teams, Opsgenie, Google Chat, Mattermost, Pushover, Pushbullet

By channel type

Each section below says which monitor and rule alerts reach that channel type, and the reason a skipped one records.

Email

Every monitor and rule alert reaches Email channels.

SMS

Reached by HTTP monitors, browser checks, heartbeat (cron) monitors, TLS certificate expiry, domain expiry, page speed, log/metric/trace alert rules and RUM issues. Skipped for DNS record changes (dns_record_channel_unsupported).

Slack

Webhook

Every monitor and rule alert reaches Webhook channels.

Discord

Reached by HTTP monitors, browser checks, TLS certificate expiry, domain expiry, page speed, log/metric/trace alert rules and RUM issues. Skipped for heartbeat (cron) monitors (heartbeat_channel_unsupported) and DNS record changes (dns_record_channel_unsupported).

Microsoft Teams

PagerDuty

Reached by HTTP monitors, browser checks, heartbeat (cron) monitors, domain expiry, DNS record changes, log/metric/trace alert rules and RUM issues. Skipped for TLS certificate expiry (tls_channel_unsupported) and page speed (page_speed_channel_unsupported).

Opsgenie

Reached by HTTP monitors, browser checks, domain expiry, log/metric/trace alert rules and RUM issues. Skipped for heartbeat (cron) monitors (heartbeat_channel_unsupported), TLS certificate expiry (tls_channel_unsupported), page speed (page_speed_channel_unsupported) and DNS record changes (dns_record_channel_unsupported).

Google Chat

Mattermost

Pushover

Pushbullet

Incidents, escalation and status pages

Incidents do not use notification channels.

Escalation steps page responders through their contact methods: email, SMS or a Slack DM with a bot token you paste in. Phone call contact methods are never used: each page to one is recorded as skipped with phone_call_not_delivered.

A service broadcasts its incidents to its own targets: a Slack channel with a bot token you paste in, a webhook URL or email.

Status page incident and maintenance notices go only to the page’s email subscribers.

Not sent to channels yet

On-call shift changes and maintenance windows do not send anything to notification channels yet, and a service’s broadcast targets cannot use a saved integration yet.

Skipped deliveries

When an alert is deliberately not sent to a channel, a receipt is recorded with the status skipped. A skipped delivery carries one of these reason codes.

Reason	Meaning	Marks the channel degraded
`heartbeat_channel_unsupported`	Heartbeat alerts cannot be sent to this channel type yet.	No
`tls_channel_unsupported`	TLS certificate alerts cannot be sent to this channel type yet.	No
`page_speed_channel_unsupported`	Page speed alerts cannot be sent to this channel type yet.	No
`dns_record_channel_unsupported`	DNS record change alerts cannot be sent to this channel type yet.	No
`not_for_paging`	An informational notice was not sent to SMS or a paging service, because those channels wake people.	No
`origin_destination`	The change was made from this destination, so it is not sent back to it.	No
`test_rate_limited`	Too many test messages were sent recently. Try again later.	No
`integration_missing`	The channel’s integration was deleted or is of the wrong type.	Yes
`integration_disabled`	The channel’s integration is turned off.	Yes
`contact_unverified`	The contact method is not verified.	Yes
`recipient_suppressed`	The address bounced or complained, or the number opted out of SMS.	Yes
`sms_quota`	The account is over its SMS quota and has no SMS credits left.	Yes
`sms_platform_limit`	Site Qwality’s own monthly SMS sending limit was reached. The problem is on our side, not in your channel.	Yes
`channel_unknown`	The channel’s type is newer than the service that read it, which happens briefly during a release. It is not a fault in your channel.	No
`source_not_supported`	This alert source cannot send to this channel type yet.	No
`phone_call_not_delivered`	Phone call contact methods are never called.	No
`channel_not_built`	This channel type is not available yet.	No
`not_a_user_channel`	A page meant for one person was not sent to a shared channel, or a shared alert to a personal contact method.	No
`subscriber_channel_not_offered`	Status pages do not offer this kind of subscription.	No

Treat a reason you do not recognise as a plain skip. Skipped receipts appear in a channel’s recent deliveries and in a monitor’s alert history, as the channels reference explains.