Mail Services

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 our mail region, which we choose for you when we set the service up, and both use DNS records on your domain to prove the mail is yours. You can hold 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 Mail Services. The list shows every Mail Hosting and SMTP Relay service on your account, and each service is one card. While a search or filter is on, a line under the heading says how many services match, such as "2 of 5". The domain on a card opens the service's panel. The line under the domain names the product and the plan, such as "Mail Hosting · Mail Starter" or "SMTP Relay · Relay 25K". For a service that Coritan manages, it reads the plan's name and "Managed by Coritan" (Coritan-managed mail services). If you own an organization, its relays are in the list too: the sending domain of its email marketing, and any relay Coritan set up for its mail.

Three tiles sit above the list. Each one is also a filter: select it to show those services, and select it again to turn the filter off. On a phone, a tile shows only its figure.

• Services counts every service, with the products in its footer, such as "2 SMTP Relay, 1 Mail Hosting". Selecting it clears every filter and the search.
• Active counts the services that are active. Its footer reads "All running", or lists the services that are not running: "2 not running yet" for services that are pending, provisioning or unpaid, and "1 suspended", such as "2 not running yet, 1 suspended".
• Needs attention counts the services with something to fix. It turns red while the count is above zero.

When a service needs attention, a strip under the tiles says "3 services need attention". It lists up to three services, or one on a phone, each with its domain, the reason and a button. Show all and the number of services filters the list to all of them. The strip is for the full list, so it is hidden while any filter, product button or search is on. It lists the worst problems first: suspended services and paused sending, then services that wait for payment, then sending under review, then services over their plan. A service needs attention when:

A service that is still being set up is not a problem. Its card says "We are setting this up. This usually takes under a minute." A service that Coritan manages has no payment or plan problem, because it has no bill.

The toolbar narrows and orders the list:

• Product buttons, All, Mail Hosting and SMTP Relay, each with a count. They appear only when your account has more than one product, and choosing one returns the list to its first page.
• The search box, "Search by domain or plan", finds a service by its domain, its plan name or its number.
• The Show menu holds All services, Active, Pending, Suspended and Needs attention, each with a count. Pending holds the services that are pending, provisioning or unpaid.
• The Sort by menu holds Name, A to Z (the default), Newest first and Problems first. Problems first uses the same order as the strip: suspended services and paused sending, then services that wait for payment, then sending under review, then services over their plan. In the table, selecting a column heading sorts by it, and the menu then names that column, such as "Sort: Status".
• Clear filters appears while a product button, Show or the search is on, and turns them off.
• Cards and Table switch how the list looks, and Refresh reads the list again. Your choice of cards or table stays in your browser. A phone always shows cards and has neither control.

The search, Show, the product, the sort and the page stay in the address, so a reload or a shared link brings them back. The address words are q, status (active, pending, suspended or attention), kind (mail or smtp_relay), sort (-created_at or attention, and none for the default) and page.

The list shows 24 services a page. When there are more, page buttons appear below it. A search or filter that matches nothing says "No matches", with a button that resets them. When Refresh fails and the list is on screen, a warning reads Could not refresh your mail services, with Try again. The list stays as it was.

A card shows the domain, a status badge such as Active or Suspended, and the line under the domain. Under them, a red or amber line says each problem from the table above, up to two. A service that is being set up shows the note "We are setting this up. This usually takes under a minute." in place of a problem. Facts follow:

A service that does not exist yet reads "Not set up yet" in place of its mailboxes or allowance. A service that is pending, provisioning, unpaid or suspended has no Sending fact.

The footer of a card holds these controls:

• A button for each problem, two at most, such as Open invoices, Contact support, See events, Open overview or Change plan.
• For an active service that is set up, Open webmail for Mail Hosting, which opens webmail in the same window (How webmail works), or Send a test for SMTP Relay, which opens its Send tab. An SMTP Relay whose sending is paused has no Send a test.
• The ... menu, named "More actions for" and the domain. It opens the service's tabs. Mail Hosting has Overview, Domains, Mailboxes, Aliases, Settings and Billing. SMTP Relay has Overview, Domains, Credentials, API keys, Webhooks, Suppressions, Events, Send and Billing. A service that Coritan manages has no Billing. A service that is not set up, or is pending, provisioning or unpaid, has only Overview and Billing. For an active service that is set up, the menu also has Add a domain, which opens the Domains tab with the add form open, and, for Mail Hosting, Create a mailbox, which opens the Mailboxes tab with the create form open. Copy domain name copies the domain.

Table shows one row for each service, with the same figures:

The last column is the ... menu from the card. Select a row to open the service. Select the heading of Domain, Product, Status or Since to sort by it.

To order, select Order Mail Hosting at the top of the list, or open the More ways to get email menu beside it and select Order SMTP Relay. Each opens the product's order page, and Order Mail Hosting is a button only until account plans open on your account. Before you sign in, the public Mail Services page and its Mail Hosting and SMTP Relay pages describe the products, with their prices from the catalogue.

While you have no mail service, the page says No mail services yet and shows a card for each product. Each card opens the same place as the matching button: Order Mail Hosting and Order SMTP Relay, or Set up free email and Set up free SMTP Relay once account plans open on your account. The More ways to get email menu stays at the top.

Once account plans open on your account, your plan includes a Mail Hosting service and an SMTP Relay service at no charge. With a mail service on the account, the page offers one main button for what to do next. Until you have your free email it is Set up free email. Then it is Add mailboxes, which opens the add-on's page for that service, and then Order SMTP Relay. The More ways to get email menu beside it holds the rest: Set up free SMTP Relay until you have it, Order SMTP Relay and Order Mail Hosting (Set up the email your plan includes). Each free service takes the sizes of your plan, and you do not choose a region. In the list, each of them has Included in your plan as its Cost. Select a domain to open its service, or open it in a new tab.

Each service is billed for its plan and renews every billing cycle until you cancel it. Until account plans open on your account, 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 where we set it up, and its mail is stored there. The order page does not ask for a region, and the service's panel shows the region's code in its header (Order Mail Hosting or SMTP Relay).
• 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.
• The Mail Hosting service your account plan includes can take extra mailboxes as add-ons (Add capacity to a service).
• 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 a mail service Coritan manages. 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.