In order to prevent negative effects (for example due to a negative rating by spam list operators) on the product domain or the domain normally used for sending emails, subdomains are used that are only used for a specific purpose, for example by a technical service provider such as contentbird GmbH or a third party commissioned by the latter.

If this domain is blocked by an (incorrect) rating with one or more mail service providers or spam list operators, the domain can easily be replaced by another subdomain in order to achieve reliable delivery again.