Configure custom channel subdomains custom-channel-subdomains

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• TL;DR: This page explains how to configure a custom channel subdomain in Journey Optimizer to enable link tracking in custom channel messages, either by using a subdomain already delegated to Adobe or by configuring a new subdomain with a DNS record.

Intents:

• Set up a custom channel subdomain to enable link tracking in custom channel messages
• Use a subdomain that is already delegated to Adobe as a custom channel subdomain
• Configure a new subdomain by generating the matching DNS record on your domain-hosting solution
• Understand subdomain statuses during processing and validation
• Prepare a subdomain to select when creating a custom channel configuration

Glossary:

• Custom channel subdomain: The subdomain you set up and then select when creating a custom channel configuration, used to enable link tracking in custom channel messages (product-specific)
• Prefix: The value that displays in your custom channel URL and is combined with a delegated subdomain to create a unique subdomain; only alpha-numeric characters and hyphens are allowed (product-specific)
• Use delegated subdomain: The Configuration type option for using a subdomain already delegated to Adobe (product-specific)
• Add your own domain: The Configuration type option for configuring a new subdomain to delegate (product-specific)
• CNAME method: A subdomain delegation method; a subdomain delegated with this method requires you to create the DNS record on your hosting platform (product-specific)

Guardrails:

• Custom channel subdomain configuration is shared between all environments, so any modification to a custom channel subdomain also impacts other production sandboxes.
• Do not use cdn or data prefixes as these are reserved for internal use; other restricted or reserved prefixes such as dmarc or spf should also be avoided.
• You cannot select a subdomain that is already used as a custom channel subdomain, and you cannot use an existing custom channel subdomain when adding your own domain.
• Capital letters are not allowed in subdomains, and delegating an invalid subdomain to Adobe is not allowed; the subdomain must be valid and owned by your organization.
• Multi-level subdomains of the same parent domain are supported (for example, custom.marketing.yourcompany.com).
• After submission, Adobe performs the required checks, which can take up to 4 hours before the subdomain can be used to send messages.
• If you select a domain that was delegated to Adobe using the CNAME method, you must create the DNS record on your hosting platform.
• When you configure a new custom channel subdomain, it always points to a CNAME record.

Terminology:

• Canonical name: Custom channel subdomain — Acronym: n/a — variants: custom channel subdomain configuration
• Do not confuse: “Use delegated subdomain” (Configuration type for a subdomain already delegated to Adobe) ≠ “Add your own domain” (Configuration type for configuring a new subdomain)
• Do not confuse: “Processing” (status shown after submission while checks run) ≠ “Success” (status once checks are successful and the subdomain is ready to use) ≠ “Failed” (status if you fail to create the validation record on your hosting solution)

FAQ:

• Q: Why do I need a custom channel subdomain? — You must set up a subdomain to enable link tracking in your custom channel messages, and you select it when creating a custom channel configuration.
• Q: What are the two ways to set up a custom channel subdomain? — You can use a subdomain that is already delegated to Adobe (Use delegated subdomain), or configure a new subdomain by adding your own domain and generating the matching DNS record.
• Q: How long does subdomain validation take? — After submission the subdomain shows the Processing status, and Adobe performs the required checks, which can take up to 4 hours before you can use it to send messages.
• Q: Which prefixes are not allowed? — Do not use cdn or data prefixes because they are reserved for internal use, and avoid other restricted or reserved prefixes such as dmarc or spf.
• Q: Does a change to a custom channel subdomain affect other sandboxes? — Yes, custom channel subdomain configuration is shared between all environments, so any modification also impacts other production sandboxes.
• Q: What happens if the DNS validation record is not created? — The subdomain is marked as Failed if you fail to create the validation record on your hosting solution.