Uptime and certificate alerts by email

hostnag emails confirmed-down, certificate and domain expiry alerts to any address, included on every plan.

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Included on every plan.

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Down

Subject: [Critical] https://www.example.com/ is down
Body: [Critical] https://www.example.com/ is down Down from 2 of 3 locations (US East, Frankfurt). Last error: unexpected_status: 503. Group: Client A Monitor: Marketing site Target: https://www.example.com/ Down since: 12 Sept 2026, 07:58 UTC Locations: US East, Frankfurt Status code: 503 Last error: unexpected_status: 503 Acknowledge: https://hostnag.com/ack/abababababababababababababababababababababababababababababababab https://hostnag.com/acme/monitors/mon-1

Set up

01
Add the address
Type the address that should receive alerts and save the channel.
02
Nothing else to set up
hostnag sends every alert its policy routes to email straight from its own address; there is no separate step to confirm the address.

What arrives

Rendered by the same code that sends it.

Back up

Subject: [Recovered] https://www.example.com/ is back up after 1 h 15 min
Body: [Recovered] https://www.example.com/ is back up after 1 h 15 min https://www.example.com/ answered again from every location. It was down for 1 h 15 min. Group: Client A Monitor: Marketing site Target: https://www.example.com/ Down since: 12 Sept 2026, 07:58 UTC Duration: 1 h 15 min Acknowledge: https://hostnag.com/ack/abababababababababababababababababababababababababababababababab https://hostnag.com/acme/monitors/mon-1

Expiring

Subject: [Critical] api.example.com certificate expires in 2 days
Body: [Critical] api.example.com certificate expires in 2 days The certificate for api.example.com expires in 2 days (14 Sept 2026). Renew it before then. Group: Client A Monitor: API Target: api.example.com Expires: 14 Sept 2026 Issuer: Let's Encrypt R11 Acknowledge: https://hostnag.com/ack/abababababababababababababababababababababababababababababababab https://hostnag.com/acme/monitors/mon-1

Recovered

Subject: [Recovered] api.example.com certificate renewed
Body: [Recovered] api.example.com certificate renewed The certificate for api.example.com is healthy again and now expires 10 Dec 2026. Group: Client A Monitor: API Target: api.example.com Expires: 10 Dec 2026 Issuer: Let's Encrypt R11 Acknowledge: https://hostnag.com/ack/abababababababababababababababababababababababababababababababab https://hostnag.com/acme/monitors/mon-1

Routing

Every alert follows the group's alert policy: which channels a route goes to and the minimum severity each one takes, in bands of critical, warning and info. Quiet hours hold non-critical alerts for email, Slack, Discord, SMS, Teams and Telegram until the window closes, then deliver one digest; critical alerts are never held, and webhook, PagerDuty and Opsgenie always deliver right away since they hand off to another machine, not a person. A maintenance window on a group or a monitor suppresses alerts for its duration while checks keep running. An alert nobody acknowledges escalates through up to three tiers, each after its own number of minutes, and can be acknowledged with one tap from the alert message itself.

Questions

Can one channel serve several groups?

Yes. Channels are org-level and routed per group, each with its own policy.

Does a downgrade remove my email channel?

No. Email is included on every plan, so it keeps working regardless of plan.

Watches

Alerting and status pagesEvery alert routed to the right channel at the right severity, held during quiet hours and maintenance, escalated until it's acknowledged.Uptime monitoringWebsites, APIs and anything that answers on a port, checked every minute from up to four places, with a failure confirmed before anyone is paged.Certificate monitoringEvery certificate hostnag can reach is watched for expiry and a swapped chain; the ones it cannot reach get a URL to report to instead.

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