Custom domains

Every identity starts on the platform domain, for example bookings.brightwell@agents.example. A tenant can move its identities to its own domain, such as bookings@brightwell.example or bookings@agents.brightwell.example, so its mail carries its own brand and builds its own sending reputation. History and threads move with the identity, and a domain change can be rolled back.

Your domain does not have to be on Cloudflare. It can stay with your registrar, Google, Microsoft, Route 53 or a web host, and keep the mailboxes it already has. Only the deployment’s platform domain must be on Cloudflare.

This guide helps you choose how to connect your domain, add it, move identities onto it, keep it healthy and fix it when something breaks.

Choose how to connect your domain

You pick a connection method when you add the domain. It decides what you change at your DNS host and how mail reaches and leaves your agents.

How the methods compare:

Not every deployment offers every method. The methods that use Amazon SES need the operator to have connected SES (Deploy to Cloudflare › Connect Amazon SES). delegated_subdomain needs a Cloudflare Enterprise account and the operator’s opt-in, and a tenant key may use nameservers only when the operator allows it. When a method is not available, adding a domain with it fails with 422 transport_unavailable, and details.reason says why. In v1.0, dns_records, smtp_relay and delegated_subdomain depend on build-time spikes (S11, S12 and S10).

A Cloudflare zone can have at most 30 mail domains (routing and sending together, including the apex).

Before you start

• You need a key with domains:write (tenant or platform) to add a domain, and identities:write to add and promote addresses.
• cloudflare_zone, nameservers and delegated_subdomain work through the Cloudflare API, so the deployment needs PM_CF_API_TOKEN, with the permissions in Deploy to Cloudflare › Create a Cloudflare API token. Without it, the request fails with 422 cf_token_required. The one exception: an operator can add a cloudflare_zone apex with pmail domains add --local-token, which then uses their local CLOUDFLARE_API_TOKEN (CLI › Commands that use your Cloudflare token). Subdomains, nameservers and delegated_subdomain always need the token on the deployment. dns_records, send_only and smtp_relay need no Cloudflare token.
• The records you publish are always read from the provider when you ask for them. Never copy records from this page or anywhere else (FR-DOM-3).

name and host: which one your DNS host wants

Every record has two forms of its name:

If you paste the full name into a form that adds your domain, the record ends up at pm-bounce.agents.brightwell.example.brightwell.example. The health check notices this and reports record_doubled_name with a fix that tells you to enter the host value only.

Add a domain

Every method follows the same four steps: add, publish, verify, move identities.

1. Add the domain.

   pmail domains add agents.brightwell.example --method dns_records --tenant brightwell
   

   or with the API:

   curl -X POST https://mail.example.com/v1/tenants/ten_01J9…/domains \
     -H "Authorization: Bearer $PYLOTA_MAIL_KEY" -H "Content-Type: application/json" \
     -d '{"name":"agents.brightwell.example","method":"dns_records"}'
   

   The domain is created in state pending. The sections below list what each method checks and what it asks you to publish.

2. Publish the records, if the method needs any:

   pmail domains records dom_01JA…
   

   {
     "data": [
       { "type": "TXT", "name": "_pylota-mail.agents.brightwell.example", "host": "_pylota-mail.agents",
         "value": "pm-verify=8f2k…", "purpose": "ownership", "required": true, "status": "ok",
         "observed": ["pm-verify=8f2k…"] },
       { "type": "MX", "name": "agents.brightwell.example", "host": "agents",
         "value": "inbound-smtp.eu-west-2.amazonaws.com", "priority": 10, "purpose": "mx",
         "required": true, "status": "missing", "observed": [] }
     ],
     "checked_at": "2026-10-09T10:05:00Z"
   }
   

   Each record’s status is ok, missing, mismatch or unexpected. Add any that are missing, correct any that are mismatch, and remove unexpected ones, which conflict (a second SPF record, for example).

3. Verify.

   pmail domains verify dom_01JA…
   

   This runs a check now (at most once a minute per domain). Checks use two independent DNS resolvers, and the state changes after two consecutive agreeing results, so it can take a few minutes. DNS changes can also take time to reach the resolvers. When verification passes and the domain becomes healthy, a domain.verified event is sent. If it passes with a warning, it becomes degraded (domain.degraded), and domain.recovered follows once the warning is fixed.

4. Move identities onto it. See Move an identity to the new domain.

A domain already on Cloudflare: cloudflare_zone

pmail domains add brightwell.example --method cloudflare_zone --tenant brightwell

Pylota Mail writes the mail records into the zone itself, so there is usually nothing to publish.

• On an apex (brightwell.example), every address reaches the Worker through one catch-all rule, and there is no limit on addresses. If the apex already has MX records, the request is refused with 409 existing_mx, because enabling routing would stop that mail. If you really mean to move the domain’s mail to Pylota Mail, repeat the request with "replace_mx": true (--replace-mx) (H5).
• On a subdomain (mail.brightwell.example), the apex’s own MX records and mailboxes are not touched. Each address needs its own routing rule, so a subdomain holds at most 200 addresses (Limits). A new address stays pending until its rule exists. If creating the rule fails, the address stays pending with reason routing_rule_failed and is retried with backoff. It is never marked active without its rule (H6).

A new domain just for mail: nameservers

pmail domains add brightwell-agents.example --method nameservers --tenant brightwell

Pylota Mail creates a Cloudflare zone for the domain, and you point the domain’s nameservers at it. This hands the whole domain to the deployment, which manages only mail records. Use it for a domain that has no website and no other mail.

• Before creating the zone, Pylota Mail looks for a website (an A or AAAA record at the name, or a CNAME, A or AAAA record at www) and for mail (MX records). If it finds any, the request is refused with 409 domain_not_dedicated, and details.records lists what it found. Moving the nameservers would stop that website or mail. If you are sure, repeat the request with "confirm_dedicated": true (--confirm-dedicated).
• The records returned are two NS records. Set them at your registrar (where you bought the domain), not at a DNS host. Reminders (domain.reminder) are sent after 24 hours, 72 hours and 7 days.
• Cloudflare deletes a zone that is not activated within 28 days. A final reminder is sent at day 21. If the zone is deleted, the domain becomes removed with reason zone_expired, and you can add it again.
• A tenant key may use this method only if the operator allows it (tenant policy domains.allow_create_zone); otherwise the request fails with 422 transport_unavailable. Pylota Mail Cloud allows it.
• If Cloudflare limits how many domains the account can add, the request fails with 429 upstream_rate_limited; try again after the time in Retry-After (3 hours).

Once the zone is active, the domain works like a cloudflare_zone apex: every address works.

A subdomain at any DNS host: dns_records

pmail domains add agents.brightwell.example --method dns_records --tenant brightwell

Mail to and from the subdomain goes through Amazon SES. Your main domain, its website and its mailboxes stay where they are. Every address on the subdomain works as soon as the domain is healthy; you do not change DNS when you add an agent.

Publish these records at your DNS host (the values come from pmail domains records):

Use a name that receives no mail today. If it already has MX records, the request is refused with 409 existing_mx. Pylota Mail cannot change your DNS, so "replace_mx": true (--replace-mx) here means “I will replace these”. Until the old MX records are gone, the domain is degraded with mx_unexpected, because mail is split between two systems.

The local part prefix pm-bounce is reserved on these domains. See also How SES domains differ.

Keep your mailbox, forward to the agent: send_only

pmail domains add brightwell.example --method send_only --tenant brightwell

Your agents answer as your existing addresses, such as bookings@brightwell.example, while your current mail system (Google Workspace, Microsoft 365 or any other) keeps receiving the mail. Pylota Mail sends through Amazon SES, signed for your domain.

1. Publish the records: the ownership TXT, three DKIM CNAMEs, and the MX and TXT at pm-bounce.brightwell.example. Your existing MX records stay as they are.

2. Add a forwarding rule in your mail system for each agent address, to that identity’s platform address, for example bookings@brightwell.example → bookings.brightwell@agents.example. The domain response shows the platform address for each address. Use a rule that forwards each message unchanged.

3. Test the forwarding once the address exists on the identity:

   pmail addresses test-forwarding bookings@brightwell.example
   

   or POST /v1/identities/{identity_id}/addresses/{address_id}/test-forwarding. Pylota Mail sends a short message, from mailer-daemon@agents.example with the subject “Pylota Mail forwarding check”, to bookings@brightwell.example. If it comes back through your forwarding rule within 10 minutes, the address’s forwarding becomes ok; otherwise failed. The test is not stored as a message and does not count as a send. Until a test or a real forwarded message arrives, forwarding is unverified.

The main drawback: forwarders that change the message. Forwarding breaks SPF for the original sender, so Pylota Mail decides trust from the sender’s DKIM signature and from ARC. A forwarder that rewrites the body (adds a footer, a disclaimer or a banner) breaks that signature. Such messages fail authentication and are quarantined by default (quarantine_reason: auth_failed), so the agent does not see them until a person releases them (Receiving › Quarantine). Prefer a mail system that forwards messages unchanged and adds ARC.

An agent replying to its own external address, which forwards back to the platform address, is caught by loop detection.

Keep your mailbox, send through your provider: smtp_relay

pmail domains add brightwell.example --method smtp_relay --tenant brightwell --inbound forward \
  --smtp-host smtp.provider.example --smtp-port 587 --smtp-username agents@brightwell.example \
  --smtp-password-stdin --probe-from agents@brightwell.example

or with the API:

{ "name": "brightwell.example", "method": "smtp_relay", "inbound": "forward",
  "smtp": { "host": "smtp.provider.example", "port": 587, "username": "agents@brightwell.example",
            "password": "…", "probe_from": "agents@brightwell.example" } }

The agents’ mail leaves through your own provider (Microsoft 365, Google Workspace, Postmark, Mailgun, SendGrid or any other with SMTP submission), with your provider’s reputation and authentication. The CLI never takes the password as an argument: it asks for it with hidden input, or reads it from standard input when you pipe it in.

What to set up with your provider:

• An account that can send by SMTP, with its user name and password. Port 465 (TLS from the start) or 587 (STARTTLS) only; port 25 is refused with 400 smtp_port_not_allowed. The relay must offer TLS: Pylota Mail never sends the credentials without it (422 smtp_tls_required). Wrong credentials give 422 smtp_auth_failed. Pylota Mail tries the login once before it stores anything, and keeps the credentials encrypted. They are never shown again.
• Permission to send as the agent addresses. If your provider limits which From addresses an account may use, allow the agent addresses and probe_from.
• DKIM for your domain. Your provider must sign with your own domain (or send with a MAIL FROM on your domain), so that DMARC passes.

The alignment probe. Pylota Mail cannot see from DNS how your provider signs, so before the first send, and then every day, it sends a probe message through your relay to the platform domain. The probe passes when the From address arrives unchanged and DMARC passes for your domain. If your provider re-signs with its own domain the issue is smtp_unaligned; if it changes the From address, smtp_from_rewritten. After a failed probe, another runs 20 minutes later. Two failed probes in a row make the domain failing (about 40 minutes from the first failure at most), and sends fall back to the platform address. Run a probe now with pmail domains probe brightwell.example (POST /v1/domains/{domain_id}/probe, at most once a minute); the result appears in pmail domains health within 15 minutes.

Inbound. With --inbound forward, your mailbox forwards to the agents exactly as for send_only, with the same forwarding test and the same drawback. With --inbound ses, you also publish the Amazon SES MX and DKIM records, as for dns_records; the MX then sends all of the domain’s mail to Pylota Mail, so use it only on a name that has no other mailboxes.

Delivery statuses. Your provider does not report deliveries back. A message is submitted once your relay accepts it, and stays submitted unless a bounce arrives (Sending › Delivery status).

Changing the password or the relay: pmail domains update brightwell.example --smtp-password-stdin (or PATCH /v1/domains/{domain_id} with smtp). The new values are used only after a probe with them passes; until then sends keep using the old ones.

A delegated subdomain: delegated_subdomain

pmail domains add agents.brightwell.example --method delegated_subdomain --tenant brightwell

The deployment gets its own Cloudflare zone for the subdomain, and you delegate the subdomain to it with NS records at your DNS host. The parent domain stays where it is. After that, the subdomain works like a cloudflare_zone apex: every address works and Pylota Mail writes the mail records.

• Available only when the deployment’s Cloudflare account is on Enterprise and the operator has set PM_CF_SUBDOMAIN_SETUP = "on". Otherwise the request fails with 422 transport_unavailable. Without it, use dns_records.
• A zone hold on your own Cloudflare account can block the zone; the request then fails with 409 zone_hold. Release the hold for subdomains and try again.
• The delegation is checked every week. If the NS records at the parent change, the domain is suspended (nameservers_changed) until you restore them and re-prove ownership.

How SES domains differ

Domains whose mail arrives through Amazon SES (dns_records, and smtp_relay with inbound: ses) behave differently from Cloudflare domains in three ways:

So on an SES domain, someone who mistypes an address gets no bounce. Tell your contacts the exact addresses your agents use.

What happens when a domain fails

Whatever the method, Pylota Mail never sends as a domain whose authentication is broken. When a domain is failing (or suspended), sends go out from the identity’s platform address instead, for example bookings.brightwell@agents.example, with the same display name, and replies still come back into the same thread (Fix a failing domain). The platform address always sends through the platform domain on Cloudflare, so fallback works for every method, including smtp_relay and SES domains.

Move an identity to the new domain

 bookings.brightwell@agents.example   primary, active ──── promote ───▶ alias, active (kept for fallback)
 bookings@brightwell.example          alias, pending ─ healthy ─▶ active ─ promote ─▶ primary, active

The platform address (bookings.brightwell@agents.example) is never retired: it is where sends go when the domain fails (When the domain fails). A later move between two of your own domains retires the old one as usual.

1. Add the address.

   curl -X POST https://mail.example.com/v1/identities/idn_01J9Z3K8V4/addresses \
     -H "Authorization: Bearer $PYLOTA_MAIL_KEY" -H "Content-Type: application/json" \
     -d '{"local_part":"bookings","domain_id":"dom_01JA…"}'
   

   CLI: pmail addresses add. The new address is an alias with status pending. It becomes active when its domain is healthy, and identity.address_activated is sent. It already receives mail once it is active. On a send_only domain (or smtp_relay with inbound: forward), add the forwarding rule and run the forwarding test now.

2. Promote it when you are ready for new mail to come from it:

   curl -X POST https://mail.example.com/v1/identities/idn_01J9Z3K8V4/addresses/adr_01JA…/promote \
     -H "Authorization: Bearer $PYLOTA_MAIL_KEY" -H "Content-Type: application/json" \
     -d '{"retire_previous_after_days":90}'
   

   CLI: pmail addresses promote. The address becomes the primary. The previous primary becomes an alias with status retiring, and its retire_at is set (default 90 days, range 0–365); if the previous primary is the platform address, it becomes an active alias instead and is never retired. Promotion needs the domain to be healthy or degraded, otherwise 409 domain_not_ready. identity.address_promoted is sent.

What changes after a promotion (FR-ADR-2):

• New threads send from the new primary.
• Existing threads keep replying from the address the other party wrote to, until it retires. A customer who answers an old message to bookings.brightwell@agents.example is answered from that address (C3).
• A retiring address keeps receiving into the same identity until retire_at. Then it becomes retired, identity.address_retired is sent, and mail to it is refused with 550 5.1.6 (on an SES domain, SES sends that bounce). The platform address keeps receiving for good.

To roll back, promote the previous address again (the retiring one, or the platform address). Any retirement is cancelled and it is the primary once more (FR-ADR-4).

To retire an alias early, use POST …/addresses/{address_id}/retire with {"after_days": 0} (CLI pmail addresses retire). The primary cannot be retired (409 address_is_primary), and the platform address can never be retired or deleted (409 address_in_use). Only a pending address that never received mail can be deleted; any other gets 409 address_in_use.

Domain health

Every domain is checked every 15 minutes and after every change, with two independent DNS-over-HTTPS resolvers. One resolver’s error or disagreement never changes the state (H7); a change needs two consecutive agreeing results.

While a domain is pending, verifying, degraded, failing or suspended, domain.reminder events are sent after 24 hours, 72 hours and 7 days in that state. Each issue carries a code, the record and an exact fix. Relay these to the person who manages the domain’s DNS: the integrator owns how the operator is told (H1).

See the current state and the history of checks:

pmail domains health dom_01JA…

{
  "state": "failing", "reason": "dkim_missing", "since": "…",
  "issues": [ { "code": "dkim_missing", "record": "cf-bounce._domainkey…", "fix": "Add TXT … with value …" } ],
  "checks": [ { "at": "…", "resolver": "cloudflare-doh", "outcome": "fail" } ],
  "fallback_active": true
}

Issues you may meet with the methods that keep DNS at your host:

The full list, per method, is in Domains on any DNS host › Health checks per method.

Fix a failing domain

1. Read the issues: pmail domains health dom_01JA… (or the issues in the domain.failing event).
2. Apply each fix at your DNS host (or, for smtp_relay, at your mail provider), exactly as given. Run pmail domains records dom_01JA… to confirm each record is ok.
3. Run pmail domains verify dom_01JA… (for smtp_relay, pmail domains probe too). After two consecutive passing checks the domain returns to healthy and domain.recovered is sent.

While the domain is failing, nothing is sent as it. Sends go out from the identity’s platform address with the same display name, flagged sent_via_fallback, and replies still thread correctly. Threads that fell back stay on the platform address until the domain is healthy and the thread has had no messages for 72 hours, so a conversation does not switch addresses back and forth (Sending › When a domain fails). If the tenant set domain_fallback: false, those sends failed instead (domain_failing_no_fallback) and must be sent again with new idempotency keys.

Re-prove ownership

A domain is suspended after 14 days of failing, or when its ownership signals change: its nameservers moved, the ownership TXT record disappeared, or its registration changed (checked weekly through RDAP) (H4). domain.suspended gives the reason: failing_14_days, nameservers_changed, ownership_record_missing or registration_changed.

Pylota Mail never sends as a domain whose ownership may have changed hands. To restore it:

pmail domains reprove dom_01JA…

This issues a new ownership TXT value for _pylota-mail.<domain>. Publish it, fix any other issues, then run pmail domains verify.

Change domains again

You can repeat the move from one custom domain to another at any time: add an address on the new domain, wait for it to become active, promote it. The previous primary retires as before.

Only one pending address per identity and domain is allowed. If you start a second change while the first address is still pending, the newer request replaces the older pending address (A11).

Remove a domain

pmail domains remove dom_01JA…

Removal fails with 409 domain_in_use while any address on the domain is active or retiring. Retire them first. Once removal starts (202), what Pylota Mail set up for the domain is deleted (the routing rules, the Email Sending onboarding and the event subscription, or the SES identity), and domain.removed is sent. Records you published at your own DNS host, and forwarding rules in your mailbox, stay until you remove them.

DMARC alignment

DMARC passes when either SPF or DKIM passes and is aligned with the domain in From.

So DKIM alignment carries DMARC on Cloudflare and SES, and the probe checks it on a relay. Before onboarding, a preflight checks the domain’s DMARC alignment tags against the transport’s DKIM domain and reports combinations that would fail (H3). Ramp the domain’s own DMARC policy as described in Deploy to Cloudflare › DNS authentication and the DMARC ramp.

FAQ

Can a tenant use its main company domain? Yes. If it already has mailboxes, use send_only or smtp_relay: the agents answer as addresses on that domain and the mailboxes keep working. Or put the agents on a subdomain with dns_records. Only a cloudflare_zone apex and nameservers take over the domain’s mail, and both refuse a domain with existing mail unless you confirm.

Does my domain have to be on Cloudflare? No. Only the deployment’s platform domain does. dns_records, send_only and smtp_relay work with any DNS host.

What happens to old threads after a domain change? They continue. Replies to the old address arrive in the same identity and are answered from the address the other party used, until it retires.

Can I undo a domain change? Yes, while the old address is still retiring: promote it again. Once it is retired, it can no longer receive mail and cannot be given to anyone else. The platform address never retires, so a move away from it can always be undone.

Why the limit of 200 addresses on a subdomain? It applies only to a cloudflare_zone subdomain. Cloudflare allows catch-all routing only on a zone apex, so each address on such a subdomain needs its own routing rule, and Cloudflare allows 200 rules per domain. A zone apex, a dns_records subdomain and a delegated subdomain have no such limit.

Does Pylota Mail ever send as a broken domain? No. A failing domain falls back to the platform address. A suspended domain sends nothing as itself until ownership is proved again.

Can operators delegate a subdomain to the deployment instead? On a Cloudflare Enterprise account, yes, with delegated_subdomain once the operator turns it on. Otherwise use dns_records.

Do I need PM_CF_API_TOKEN? For cloudflare_zone, nameservers and delegated_subdomain added through the API, yes; its permissions are in Deploy to Cloudflare. Without it, an operator can still add a zone apex with pmail domains add --local-token and their local token; subdomains, nameservers and delegated_subdomain need the token on the deployment. dns_records, send_only and smtp_relay do not use it.

Do I need an AWS account? The operator does, for dns_records and send_only (and smtp_relay with inbound: ses). Tenants do not.