Why Does Clicking the Unsubscribe Link in a CRM Approved Email Result in an HTTP 400 Error?
If the Unsubscribe record is configured to specify the Unsubscribe Message Identifier as shown in the example below:
Token in Approved Document
If there are any blank spaces in the Unsubscribe Identifier field it will result in an HTTP 400 error when the recipient clicks "Unsubscribe". To resolve the error, consider using an underscore or removing the blank space from the Unsubscribe Identifier field.
- CRM Help Documentation: Displaying Products on the Unsubscribe Page
- CRM Help Documentation: Embedding the Unsubscribe Page