Email System

class EmailCampaign(CremeEntity):
    """
    Email campaign for mass communications.

    Attributes:
    - name: str, campaign name
    - subject: str, email subject line
    - body: TextField, email content
    - mailing_lists: ManyToMany, target mailing lists

    Methods:
    - send(): Execute email campaign
    - get_recipients(): Get all campaign recipients
    """

class EmailTemplate(CremeEntity):
    """
    Email template for consistent messaging.

    Attributes:
    - name: str, template name
    - subject: str, email subject template
    - body: TextField, email body template

    Methods:
    - render(context): Render template with context
    """