Email

Coritan has two mail products. Mail Hosting gives people mailboxes on your own domain, which they read in a mail app or in webmail. SMTP Relay sends the mail your software writes, such as receipts, password resets and newsletters, over SMTP or an HTTPS API, and reports what happened to each message.

Both run in the region you choose when you order, and both use DNS records on your domain to prove the mail is yours. You can order more than one of each.

Start here:

• Order Mail Hosting or SMTP Relay
• Mail DNS records: what each record is for and how to publish it
• How the DMARC stage ramp works

Mail Hosting:

• How Mail Hosting works
• Add a domain to Mail Hosting
• Create and manage mailboxes
• Secure a mailbox with two-factor sign-in and app passwords
• Forward addresses with aliases
• Connect a mail app
• Move existing mail into a mailbox
• Change Mail Hosting settings

SMTP Relay:

• How SMTP Relay works
• Add a sending domain
• Send over SMTP with credentials
• Create and revoke send API keys and send email over HTTPS
• Transactional and marketing mail
• Receive delivery events with webhooks, look up message events and manage the suppression list
• How sending limits work and request a higher hourly limit
• Sending reputation and deliverability

Webmail:

• How webmail works, from getting a free coritan.gg mailbox to filters and keyboard shortcuts

When something goes wrong, see Troubleshoot mail.

In the dashboard, go to Email. The list shows every Mail Hosting and SMTP Relay service on your account, with its Domain, Product, Status, Plan and Since date. Filter it by status, or search by domain or plan. Select a row to open the service's panel.

The Plan column says what the service holds: a count of mailboxes for Mail Hosting, and the monthly email allowance for SMTP Relay. A service that is still being set up reads Not set up yet.

To order, select Order Mail Hosting or Order SMTP Relay at the top of the list. Each opens the product's order page. The public Mail page lists the current plans before you sign in.

Each service is billed for its plan and renews every billing cycle until you cancel it. SMTP Relay's order page also offers a free plan. How Mail Hosting and SMTP Relay are billed covers plan changes, the monthly sending allowance and cancelling.

• A service lives in the region you chose when you ordered it, and its mail is stored there.
• Prove you own a domain and publish its records before you send from it. A domain counts as verified once its ownership, SPF and DKIM checks pass, and for Mail Hosting its MX check too. See Mail DNS records.
• A domain can be on one mail service at a time. To use a domain on both products, give the relay a sending subdomain, such as send.example.com.
• The plan sets how many domains, mailboxes or SMTP credentials the service may hold. The panel shows each count against its limit.
• Coritan pauses a service's sending when its bounce or complaint rate crosses the platform's limit. See Sending reputation and deliverability.

List your mail services:

curl https://api.coritan.com/api/v1/client/mail/services \
  -H "Authorization: Bearer $CORITAN_TOKEN"

GET /client/smtp-relay/services returns the same list. Both answer {"items": [...], "total": n} with one item for every Mail Hosting and SMTP Relay service on your account:

{
  "items": [
    {
      "service_id": 4812,
      "tenant_id": 97,
      "internal": false,
      "module_name": "smtp_relay",
      "product_name": "Relay 50K",
      "status": "active",
      "hostname": "send.example.com",
      "tenant": { "...": "..." },
      "created_at": "2026-09-01T10:12:00"
    }
  ],
  "total": 1
}

module_name is mail for Mail Hosting and smtp_relay for SMTP Relay. Use service_id as {service_id} in every other mail request. The two prefixes share one set of routes, so /client/mail/{service_id}/... and /client/smtp-relay/{service_id}/... reach the same service. An operation that belongs to the other product answers 400 or 404 with a message that says so, such as Mailboxes are only available on Mail Hosting services.

An item with "internal": true and "service_id": null is an internal mail tenant. Reach it through /client/platform-mail/{tenant_id}/... instead.

A service that is still being set up answers 409 This mail service is still provisioning. See Authentication for tokens.