On this page: Learn how to define personalized values for dynamic subdomains, header parameters, and URL tracking parameters at the email channel configuration level.
For increased flexibility and control over your email settings, Journey Optimizer allows you to define personalized values for subdomains, headers and URL tracking parameters when creating email configurations.
Add dynamic subdomains dynamic-subdomains
When creating an email configuration, you can set up dynamic subdomains based on specific conditions.
For example, if you have legal constraints to send messages from a dedicated email address per country, you can use dynamic subdomains. This allows you to create a single configuration with several sending subdomains corresponding to different countries - instead of creating multiple configurations for each country. You can then target customers based in various countries consolidated into one campaign.
To define dynamic subdomains in an email channel configuration, follow the steps below.
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Before creating a configuration, set up the subdomains you want to use for sending emails according to your use case. Learn how
For example, let’s say you want to use different subdomains for different countries: set up one subdomain specific to US, one specific to UK, etc.
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Create a channel configuration. Learn how
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Select the Email channel.
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In the Subdomain section, enable the Dynamic Subdomain option.
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Select the Edit icon next to the first Condition field.
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The personalization editor opens. In this example, set a condition such as
CountryequalsUS.
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Select the subdomain you want to associate with this condition. Learn more about subdomains
note NOTE Certain subdomains are currently unavailable for selection due to pending feedback loop registration. This process may take up to 10 business days. Once complete, you can choose from all available subdomains. 
All recipients based in the US will receive messages using the selected subdomain for that country, meaning that all URLs involved (such as mirror page, tracking URL or unsubscribe link) will be populated based on that subdomain.
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Set other dynamic subdomains as wanted. You can add up to 50 items.
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Define all other email settings and submit your configuration.
Once you have added one or more dynamic subdomains to a configuration, the following items will be populated based on the resolved dynamic subdomain for this configuration:
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All URLs (resource URL, mirror page URL and tracking URL)
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The unsubscribe URL
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The From email and Error email suffixes
Personalize your header personalize-header
You can also use personalization for all the header parameters defined in a configuration.
- All Header parameters and optional Sender headers fields can be personalized, except the Error email prefix field.
- When editing an email configuration, you cannot add new profile attributes to header parameters — you must create a new channel configuration instead.
For example, if you have multiple brands, you can create a single configuration and use personalized values for your email headers. This allows you to make sure that all emails sent from your different brands are addressed to each of your customers with the correct From names and emails. Similarly, when your recipients hit the Reply button in their email client software, you want the Reply to names and emails correspond to the correct brand for the right user.
To use personalized variables for your configuration header parameters, follow the steps below.
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Define your header parameters as you would usually do. Learn how
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For each field, select the Edit icon.
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The personalization editor opens. Define your condition as wanted and save your changes.
note NOTE You can only select Profile attributes and Helper functions. For example, you want to handle dynamically emails sent on behalf of a relationship manager, whose details are stored in the customer profile, so that every customer is linked to a relationship manager. In a journey, the email header (sender name, sender email, reply to address) can be personalized with the relationship manager’s parameters, taken from the profile attributes.
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Repeat the steps above for each parameter you want to add personalization to.
Use personalized URL tracking personalize-url-tracking
To use personalized URL tracking parameters, follow the steps below.
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Go to the URL tracking parameters section of your email channel configuration. Learn more
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Click the Edit icon next to each field. In addition to contextual attributes, you can select profile attributes.
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Select the profile attribute of your choice from the personalization editor.
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Repeat the steps above for each tracking parameter you want to personalize.
Now when the email is sent out, the personalized parameter will be automatically appended to the end of the URL. You can then capture this parameter in web analytics tools or in performance reports.
View configuration details view-surface-details
When using a configuration with personalized settings in a campaign or a journey, you can display the configuration details directly within the campaign or the journey. Follow the steps below.
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Select the Edit content button.
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Click the View configuration details button.
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The Delivery settings window displays. You can view all the configuration settings, including the dynamic subdomains and personalized header parameters.
note NOTE All information on this screen are read-only. -
Select Expand to display the dynamic subdomains’ details.
Check your configuration check-configuration
When using a personalized configuration in a campaign or a journey, you can preview your email content to check for potential errors with the dynamic settings you defined. You can use either simulation method:
- Click Simulate content to test content variations with sample input data or AI auto-generation. Learn how to simulate content variations
- Click Simulate content, then select Simulate content (AEP profiles) from the dropdown to preview with test profiles.
To preview your content using test profiles, follow these steps:
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Select a test profile.
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If an error is displayed, click the View configuration details button.
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Check the Delivery settings screen for the errror details.
Possible errors can be as follows:
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The subdomain did not resolve for the selected test profile. For example, your configuration uses several sending subdomains corresponding to different countries, but the selected profile has no value defined for the
Countryattribute, or the attribute is set toFrancebut this value is not associated with any subdomain in that configuration. -
The selected profile has no associated values for one or more header parameters.
With any of these errors, email is not sent to the selected test profile.
To avoid this type of error, make sure the header parameters you define use personalized attributes with values for most of your profiles. Missing values can impact your email deliverability.
This section contains structured knowledge intended to support interpretation, retrieval, and question answering related to this topic.
For complete understanding, this information should be combined with the documentation on this page. Neither source is intended to stand alone; the page describes the feature, while this section provides additional context that helps disambiguate terminology, intent, applicability, and constraints.
- TL;DR: This page explains how to define personalized values for dynamic subdomains, header parameters, and URL tracking parameters at the email channel configuration level, and how to view and check those settings in a campaign or journey.
Intents:
- Set up dynamic subdomains based on conditions in an email channel configuration
- Personalize email header parameters in a configuration
- Personalize URL tracking parameters in a configuration
- View read-only configuration details from within a campaign or journey
- Check a personalized configuration for errors using content simulation
Glossary:
- Dynamic Subdomain: A configuration option that lets you set up multiple sending subdomains selected by conditions defined in the personalization editor, instead of creating a separate configuration per case (product-specific)
- Header parameters / Sender headers: Configuration fields (for example From and Reply to names and emails) that can be given personalized values (product-specific)
- URL tracking parameters: Configuration-level parameters that are automatically appended to the end of content URLs and can be personalized with profile attributes (product-specific)
- Simulate content: The action to test content variations with sample input data or AI auto-generation (product-specific)
- Simulate content (AEP profiles): The option (from the Simulate content dropdown) to preview content with test profiles (product-specific)
Guardrails:
- You can add up to 50 dynamic subdomains per configuration.
- All Header parameters and optional Sender headers fields can be personalized, except the Error email prefix field.
- When editing an email configuration, you cannot add new profile attributes to header parameters — you must create a new channel configuration instead.
- For header personalization, only Profile attributes and Helper functions can be selected.
- If you disable the Dynamic Subdomain option after setting up dynamic subdomains, all dynamic values are removed; select a subdomain and submit the configuration for the change to take effect.
- Certain subdomains may be unavailable for selection due to pending feedback loop registration, which may take up to 10 business days.
- If a subdomain does not resolve for a selected test profile, or a profile has no value for a required header parameter, the email is not sent to that test profile.
- When dynamic subdomains are configured, the From email and Error email suffixes are populated from the resolved dynamic subdomain; Sender email, when set, is a full address and is not built from that subdomain suffix.
Terminology:
- Canonical name: Personalize email configuration settings — Acronym: n/a — variants: surface personalization, dynamic subdomains, personalized header, personalized URL tracking
- Synonyms: “Simulate content (AEP profiles)” = “preview with test profiles”
- Do not confuse: “Simulate content” (test content variations with sample input data or AI auto-generation) ≠ “Simulate content (AEP profiles)” (preview using test profiles)
- Do not confuse: “From email / Error email suffixes” (built from the resolved dynamic subdomain) ≠ “Sender email” (a full address, not built from that suffix)
FAQ:
- Q: How many dynamic subdomains can a configuration have? — Up to 50.
- Q: Which header field cannot be personalized? — The Error email prefix field; all other Header parameters and optional Sender headers fields can be personalized.
- Q: Can I add a new profile attribute to header parameters when editing a configuration? — No; you must create a new channel configuration instead.
- Q: What happens if I disable the Dynamic Subdomain option? — All dynamic values are removed; select a subdomain and submit the configuration for the change to take effect.
- Q: How do I check a personalized configuration for errors? — Preview the content using Simulate content, or Simulate content then Simulate content (AEP profiles) with a test profile; view details on the read-only Delivery settings screen.
- Q: Why might a subdomain not resolve for a test profile? — The profile has no value for the attribute used in the conditions (for example Country), or its value is not associated with any subdomain in the configuration; in that case the email is not sent to that test profile.