@register.filter(name='secure_mail')
@stringfilter
def secure_mail(value):
    """
    Returns a somewhat safer email address
    
    Usage:
    
        {{ "mailto:me@domain.com"|secure_mail }}
    
    Outputs:
        
        &#109;&#97;&#105;&#108;&#116;&#111;&#58;&#109;&#101;&#64;&#100;&#111;&#109;&#97;&#105;&#110;&#46;&#99;&#111;&#109;
    
    """
    try:
        return "".join(["&#%s;" %(ord(c)) for c in value])
    except:
        return value
secure_mail.is_safe = True # because "&" is renderd with autoescape by default