Receiving Domains

GreenArrow CloudMTA

This feature is only available on GreenArrow CloudMTA.

Receiving Domains allow you to receive email through GreenArrow at your domain. When a Receiving Domain’s DNS is verified, GreenArrow automatically creates an Incoming Email Domain so that mailboxes under that domain can receive email.

Each Receiving Domain gets its own DNS code, which GreenArrow uses to route inbound connections through its receiving infrastructure. You add a single MX record pointing your domain at GreenArrow’s mail exchanger, and GreenArrow handles the A record behind that MX target. An MX record (rather than a CNAME) is used so that you can also host your own website at the domain.

Getting Started: Full Lifecycle

1. Create a Receiving Domain

Create a Receiving Domain via the API or UI, specifying at minimum the domain field.

GreenArrow will automatically:

Generate a unique 12-character DNS code for the domain.
Compute the MX record you must add to your DNS zone.

2. Retrieve the Required DNS Record

Fetch the domain’s DNS records from the API (GET /ga/api/v3/eng/receiving_domains/{id}) or view them in the UI. The record returned in dns_records shows exactly what must be added to your DNS zone.

The record includes:

bind — the full BIND zone file syntax, ready to paste.
type — always MX for Receiving Domains.
name — the DNS hostname (your domain).
value — the MX priority and target hostname on GreenArrow’s receiving infrastructure.

3. Add the Record to DNS

Add the provided MX record to your DNS provider. Only that single record needs to be configured — GreenArrow manages the A record behind the MX target.

4. Verify DNS

GreenArrow automatically checks DNS every 15 minutes. You can also use the Check DNS API to request an immediate check:

GET /ga/api/v3/eng/check_dns/{domain}?recheck_now=1

DNS lookups are performed against the domain’s authoritative nameservers directly (not the local resolver) with a 10-second timeout. The response shows the record’s verified status.

Once the MX record is verified, dns_verified is set to true. This is a one-way flag — it never returns to false, even if DNS later regresses.

5. Automatic Provisioning on Verification

When dns_verified first becomes true, GreenArrow automatically creates an Incoming Email Domain for the Receiving Domain’s domain. This enables mailboxes on that domain to receive inbound email.

Fields Reference

domain
string
/
immutable

The domain that will receive inbound email.

Must be unique (case-insensitive). Example: receive.example.com

cname_suffix_domain
string
/
immutable
/
default: "dnsforemail.com"

The domain under which GreenArrow’s receiving infrastructure is hosted; the MX target for this domain is a hostname under this suffix. The field is named cname_suffix_domain — rather than something MX-specific — for consistency with the Sending Domains API, where the same suffix scopes CNAME records. (In the UI it is labeled “MX Target Domain”.)

dns_verified
boolean
/
read-only

true once the MX record has been verified. This is a one-way flag — it never returns to false.

dns_regression
boolean
/
read-only

true if the domain was previously verified but the MX record is no longer correct. Cleared when the record is fixed.

dns_records array of hashes
/
read-only

The DNS record that must be added to your DNS zone.

bind string	BIND zone file syntax.
type string	The DNS record type. Always `MX` for Receiving Domains.
name string	The DNS hostname (your domain).
value string	The expected MX value — the priority and target hostname (for example, `10 mx.abc123def456.dnsforemail.com`).
verified boolean	Whether the record is currently correct.

DNS Record Created for Receiving Domains

{domain}.  IN  MX  10 mx.{dns_code}.{cname_suffix_domain}.

GreenArrow manages the A record at the MX target. This means the receiving infrastructure can be updated without requiring additional DNS changes on your end.

Uniqueness

The tracking domain and DKIM domains for Sending Domains and Receiving Domains may not have conflicting domain names. This means, for example, if you have a tracking domain named trk.example.com, you may not create a Receiving Domain named trk.example.com, and visa versa.

Deletion Behavior

Deleting a Receiving Domain removes the associated Incoming Email Domain if it has no mailboxes. If the Incoming Email Domain has mailboxes, it is preserved so that existing mailboxes continue to function.