Configuring your store to avoid sending multiple marketing e-mails to the same e-mail address
By adding a new attribute to the WebSphere Commerce configuration file, you can prevent the server from sending multiple e-mails to the same address for the same e-mail activity, even when the e-mail address belongs to different users. This ensures that a customer who registers as more than one user but supplies the same e-mail address for each user receives only one e-mail per e-mail activity.