Custom sending domain
Send outage-recovery emails to your users from your own mail server and domain.
error.page can email your users when an outage they hit is resolved — the "notify me when it's fixed" opt-in from your branded page. With a custom sending domain, those emails go out through your mail server, so they arrive from status@yourcompany.com instead of error.page. Better deliverability, on your brand.
Custom sending domains are available on the Pro plan and above — the same audience as custom domains.
What it's for
- Outage recovery notifications — when an incident auto-resolves, the users who left their email during it get a "we're back" note, sent from your domain.
- Any future customer-facing mail is routed the same way.
Your own account emails (login, security) always come from error.page — this setting only affects mail sent to your users.
Configure it
Under Sending Domain in the dashboard, enter your SMTP details:
| Field | Notes |
|---|---|
| SMTP host | e.g. smtp.postmarkapp.com, email-smtp.us-east-1.amazonaws.com, smtp.sendgrid.net |
| Port / Encryption | 587 with STARTTLS (recommended), or 465 with SSL/TLS |
| Username / Password | Your provider's SMTP credentials or API key. The password is stored encrypted (AES) and never shown again. |
| From address | The address your users see, e.g. status@yourcompany.com |
| From name | Optional display name, e.g. your product name |
Tick Enabled to route recovery notifications through it, then Send a test — a successful test marks the domain Verified.
Deliverability: SPF & DKIM
For mailbox providers to trust mail sent from your domain, add the DNS records your SMTP provider gives you:
- SPF — a TXT record authorising your provider to send for your domain.
- DKIM — the CNAME/TXT keys your provider issues, so messages are cryptographically signed.
- Optionally DMARC — a policy record that ties SPF/DKIM together.
Without these, recovery emails may land in spam. Every major provider (Postmark, SES, SendGrid, Resend, Mailgun) documents the exact records to add.
How sending works
When an incident is auto-resolved, error.page relays the recovery notice through your configured server — each project uses its own connection, and a delivery failure never blocks incident resolution. If the sending domain isn't enabled, no recovery emails are sent.
Removing it
Remove the sending domain any time from the dashboard. Recovery notifications stop immediately; nothing else about your project changes.