Receiving Custom Domains

Use a custom domain or subdomain for inbound addresses that route into OpenSend-backed storage.

DNS records

Inbound email routing uses MX records. If the same root domain already receives human mailbox traffic elsewhere, use a subdomain such as inbound.example.com or agents.example.com to avoid disrupting existing mailboxes.

Example DNS shape:

Host	Type	Value
`inbound.example.com`	MX	`inbound-smtp.<region>.amazonaws.com` for hosted SES receiving.
`inbound.example.com`	TXT	Optional provider verification record.

Tenant mapping

OpenSend received-email rows must include the tenant user_id. Your inbound worker should map recipients or domains to the OpenSend user that owns the domain before inserting rows.

Dashboard status

When receiving is enabled, hosted OpenSend provisions an SES receipt rule for the domain. The creator still adds the shown MX record so inbound mail reaches SES. Self-hosted operators must configure SES_INBOUND_SNS_TOPIC_ARN and S3_BUCKET_NAME or SES_INBOUND_BUCKET_NAME, subscribe the inbound SNS topic to /events/inbound/ses-s3, and grant SES permission to write raw MIME objects to the bucket.

Routing rules

After the domain is verified and receiving is enabled, create exact, alias, or catch-all routes from the Receiving page or /api/receiving/routes. Routes are tenant-scoped and evaluated in this order: exact address, alias, catch-all, then unrouteable. OpenSend records route decisions on received email rows for later audit and processing.