Skip to main content
By default, inboxes use @omail.sh addresses. With a custom domain you can use any domain you own — for example agent@yourdomain.com.

​
How it works

  1. Add your domain in the dashboard or via the API
  2. OpenMail returns the DNS records you need to set
  3. Publish them. The domain verifies automatically once DNS is live
  4. Create inboxes on it by passing the domain when you create an inbox

​
Adding a domain

Go to Settings → Domains in the dashboard and click Add domain. Enter the domain you want to use (e.g. mail.acme.com). You can also add it with POST /v1/domains.
You can use a subdomain like mail.acme.com or an apex domain like acme.com. A subdomain is generally easier to configure without affecting other email on your domain.
After adding your domain, OpenMail returns the DNS records to set at your registrar.

​
DNS records

Always prefer the exact records shown in the dashboard or API after you add the domain — those values are authoritative. MX record on your domain routes inbound email to OpenMail. DKIM records are three CNAMEs under _domainkey (hosts like omail._domainkey). They add a cryptographic signature to outbound email, proving messages were sent by you. The hosts and targets are unique per domain and provided after you add it. MAIL FROM records (bounce MX + TXT) set the envelope sender on your domain so SPF can align. Publish both on the bounce host exactly as shown — do not put the SPF include on your apex unless the records tell you to. Merge the SPF include into any v=spf1 record you already have; two SPF records on the same host are invalid. DMARC record tells receivers what to do with mail that fails SPF or DKIM. Google and Yahoo require bulk senders to publish one. The default p=none; satisfies the requirement without affecting delivery; tighten to quarantine or reject once SPF and DKIM are aligned. If your domain already has a _dmarc record, keep it rather than replacing it. See SPF, DKIM, DMARC. DNS changes typically propagate within minutes but can take up to 48 hours.

​
Verifying your domain

You don’t need to click Verify. Once the records are published, OpenMail checks them in the background and the domain becomes Verified within a couple of minutes. Click Verify only if you want to check sooner.
DMARC is your own published policy, so it is not checked during verification — a domain verifies without it. The record is shown because bulk-sender requirements expect one.
If verification fails, double-check each record at your registrar and try again. Common issues:
  • Existing MX records on the domain that weren’t replaced
  • MAIL FROM MX or SPF published on the apex instead of bounce
  • Only one of the three DKIM CNAMEs published, or a host copied without the subdomain suffix
  • Two v=spf1 TXT records on the same host (only one is allowed — merge includes into a single record)

​
Using your domain

Once a domain shows as Verified, it is ready to use — there is no separate activation step. Verifying the domain is what makes it available. Your account default domain never switches automatically. To create an inbox on your custom domain, choose it explicitly:
The resulting address uses your domain:
If you omit domain, the inbox is created on your account default domain (@omail.sh). Passing a domain that is not verified, does not belong to your account, or is scoped to a different pod returns invalid_domain.

​
Pod scoping

Custom domains can be shared across your account or limited to a single pod: When adding a domain, pick All pods or a specific pod. On a pod’s detail page, the Domains tab lists domains scoped to that pod; account-wide domains still appear when creating inboxes inside the pod. To move a scoped domain to another pod (or make it account-wide), reassign it in the dashboard. Narrowing scope is blocked while inboxes on that domain live outside the target pod.

​
Limits

Custom domains are available on the Pro plan and above.

​
Removing a domain

You can delete a custom domain from the dashboard or API as long as it has no inboxes. Delete the inboxes on that domain first, then remove the domain. Deleting a domain removes it from OpenMail but does not delete your DNS records — you can remove those from your registrar separately.