Custom Domains
Send and receive email from your own domain instead of robotomail.co.
Platform email vs custom domain
By default, every account gets a platform email address: slug@robotomail.co. This address works immediately with no DNS configuration.
Custom domains let you send from addresses like agent@yourdomain.com. This requires the paid plan, DNS configuration, and domain verification.
Required DNS records
- MX record— Points your domain to Robotomail's inbound mail server
- SPF (TXT) — Authorizes Resend to send on your behalf:
v=spf1 include:amazonses.com ~all - DKIM (CNAME or TXT) — Resend provides DKIM records that may be CNAME or TXT type depending on the domain configuration. These prove emails are unmodified and authorized. SPF and the feedback MX record go on a
sendsubdomain (e.g.send.yourdomain.com). - DMARC (TXT) — Policy for handling authentication failures:
v=DMARC1; p=quarantine; rua=mailto:dmarc@robotomail.com
Verification process
After adding a domain via POST /v1/domains, you receive the DNS records to configure. A background job checks verification every 5 minutes, or you can trigger it manually via POST /v1/domains/:id/verify.
Once MX, SPF, and DKIM are verified locally, the domain moves to DNS_VERIFIED. After Resend confirms provider-side verification, the status becomes VERIFIED and you can create mailboxes on it. DMARC is recommended but not required.
Email domain basics
In support@agents.example.com, support is the mailbox name and agents.example.com is the email domain. A website and email can use the same domain while pointing at different services. Buying a domain does not itself create working mailboxes.
DNS publishes the records other systems use to locate and authenticate email. MX records route incoming mail. SPF identifies authorized sending infrastructure, DKIM verifies a message signature and DMARC applies alignment and reporting policy. Follow the records returned for your specific Robotomail domain rather than copying sample values from a generic guide.
Domains and subdomains
A subdomain is a name below another domain, such as agents.example.com below example.com. It can have its own email routing. An address at support@agents.example.com is different from support@example.com.
Use a dedicated subdomain when your root domain already receives employee mail. Configure the exact domain you intend to use in Robotomail and add records at the authoritative DNS provider. Editing a website's A or CNAME record does not create an email mailbox or change its MX route.
SPF, DKIM and DMARC
SPF is a TXT record that identifies systems authorized to send for an envelope domain. Publish one SPF policy per hostname. If multiple services legitimately send, merge their requirements into one valid policy rather than publishing competing SPF TXT records. Respect DNS lookup limits and avoid broad authorization.
DKIM signs selected headers and the message body. A selector identifies the public key in DNS. Publish the records Robotomail returns exactly; do not substitute a private key or reuse another domain's selector values.
DMARC checks alignment between the visible From domain and a passing SPF or DKIM identity. It also lets a domain request handling and aggregate reports. Start with an inventory of legitimate senders, monitor results and tighten policy only when you understand the effect. DMARC is recommended; do not describe it as a required Robotomail domain-verification record unless the current setup response requires it.
Authentication helps establish identity. It does not guarantee inbox placement, verify the truth of an email or grant its author permission to instruct an agent.
Wildcard DNS and mailbox addresses
A wildcard DNS record can answer some otherwise unmatched names beneath a domain. It does not create Robotomail mailboxes, make every address valid or replace custom-domain verification for the domain you registered.
An email catch-all and a DNS wildcard are different concepts. Use explicitly provisioned mailboxes and the exact DNS records required by Robotomail. Do not assume that publishing *.example.com automatically provisions or authenticates email across arbitrary subdomains.