Add Header Action
The Add Header action adds a custom header to the received email. You typically use this action only in combination with another action. This action has the following options.
Header name—The name of the header to add. It must be between 1 and 50 characters, inclusive, and consist of alphanumeric (a-z, A-Z, 0-9) characters and dashes only.
Header value—The value of the header to add. It must be less than 2048 characters, and must not contain newline characters ("\r" or "\n").