The date formatter service. Type:

public MessageInterface::isPersonal()

protected ContactFormEditForm::getEditableConfigNames()

List of recipient email addresses. Type:

public MessageInterface::getSubject()

public ContactFormInterface::getWeight()

public ContactForm::getMessage() Returns

public ContactFormInterface::setRecipients($recipients)

public MessageForm::validateForm(array &$form, FormStateInterface

public Message::copySender() Returns