Skip to content
SuperMail docs

Custom domains overview

A custom domain in SuperMail is a domain you own (e.g. yourdomain.com) that you’ve attached to your workspace. Once configured, you can:

  • Receive mail at any address on that domain (catch-all or per-alias).
  • Send mail from any address on that domain.
  • Reply from the address the original message was sent to.

Custom domains are the core of the multi-domain workflow. Each custom domain you add uses one of your plan’s account slots - the same pool you’d otherwise spend on personal mailboxes like Gmail or Outlook. There is no separate domain quota; on a 3-slot plan you could go all domains, all mailboxes, or any mix. See Plans and billing for slot counts per plan.

How it works under the hood

  • Outbound: we provision an AWS SES verified identity per domain and sign outbound mail with DKIM keys SES manages for us. Your DNS has the public DKIM selectors; the private keys stay in SES.
  • Inbound: your domain’s MX records point at our receiving endpoint. Incoming mail hits SES → S3 → a processing queue → the SuperMail inbox. End-to-end latency is typically under 10 seconds.

The steps

  1. Add a domain to your workspace.
  2. Configure DNS records (MX, DKIM, SPF, DMARC).
  3. Verify - we check DNS and enable the domain once records propagate.
  4. Set up sending (add send profiles for your addresses).
  5. Configure receiving (catch-all vs per-alias routing).

When something goes wrong, see Troubleshooting.