Because of the large amount of email they receive, many legislators have web forms that require alert emails to contain certain information such as a topic or the name of the organization that initiated the alert. This information improves the legislator's ability to sort and respond to emails. Most web forms require at least the subject of the alert, but the White House and Congress have additional requirements.
As well as a topic, White House web forms require organization name and mission, and Congressional web forms require the organization name and mission, and the name, phone number, and email address of a contact within the organization.