Email Notifications
Assert emails an alert when a monitor fails, and again when it recovers. Email works on every plan, including the free one. Nothing to install, and past incidents stay searchable in your inbox.
The email names the assertion that failed, the expected value, the value your API returned, the regions that agreed, and the time. A failure re-runs across regions before the email goes out. You get one email per incident, not one per failed check, and the incident closes itself when the assertion passes again.
Send to several addresses or a team alias, and turn on a daily or weekly digest of monitor health.
Setup Guide
Step 1: Add an Email Channel
- Go to Alerts → Channels in your Assert dashboard
- Click Add Channel → Email
- Enter the recipient addresses
Step 2: Configure Recipients
A channel accepts more than one recipient:
[email protected]
[email protected]
[email protected]
Use + tags to filter the mail in Gmail or Outlook.
Step 3: Set Preferences
Choose what triggers an email:
- Failures, when a monitor fails. On by default.
- Recoveries, when a monitor passes again. On by default.
- Warnings, for slow responses and threshold breaches. Off by default.
Step 4: Assign to Monitors
Open each monitor. Add the email channel under Alert Channels.
Email Format
The email looks like this:
Subject: 🔴 Monitor Failed: Production API
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MONITOR FAILURE DETECTED
Monitor: Production API
URL: https://api.example.com/health
Status: 500 Internal Server Error
Response Time: 2,340ms
Region: US East
Time: Dec 11, 2024 at 2:34 PM UTC
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WHAT FAILED
Assertion: $.status == "success"
Expected: "success"
Received: "error"
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[View Monitor] [Acknowledge Alert]
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Configuration Options
| Option | Description |
|---|---|
| Recipients | Comma-separated email addresses |
| Alert on Failure | Send email when monitor fails |
| Alert on Recovery | Send email when monitor recovers |
| Include Response Body | Attach response data (truncated) |
| Include Headers | Show response headers in email |
Best Practices
Send to a team alias such as [email protected] or [email protected] rather than to [email protected]. One person's inbox is a single point of failure.
Set Up Email Filters
Create inbox rules to sort the alerts:
Gmail:
From: [email protected]
Label: API-Alerts
Skip Inbox: (optional)
Outlook:
From: [email protected]
Move to: Monitoring/Alerts
Use +Tags for Routing
Many email providers support + tags:
[email protected] → Production alerts
[email protected] → Staging alerts
[email protected] → Critical only
Don't Rely on Email Alone
Email can be delayed or filtered. Pair it with Slack for team visibility, or with PagerDuty for on-call escalation.
Troubleshooting
Not receiving emails?
- Check the spam and junk folders
- Check the email address
- Add
[email protected]to your contacts - Check whether your provider blocks bulk mail
Too many emails?
- Increase the monitor check interval
- Turn on alert cooldowns to stop duplicate notifications
- Use Slack or Discord for real-time alerts, and email for the digest
Emails delayed?
- Email delivery is not instant. Expect one to two minutes.
- For faster alerts, use Slack, Discord, or webhooks
Next Steps
- Set up Slack for instant team alerts
- Configure PagerDuty for on-call escalation
- Learn about alerting best practices
