Example

mailSieveRuleSource: require ["fileinto", "reject",
                                           "redirect", "discard]
if header :contains "Subject" "New Rules Suggestion
    {redirect "rules@sesta.com" # Forward message }
if header :contains "Sender" "porn.com"
   {discard text: 
      Your message has been rejected.
      Please remove this address from your mailing list.
    # Reject message, send reply message.}
if size :over 1M
    { reject text:
      Please do not send me large attachments.
      Put your file on a server and send me the URL.
      Thank you.
    # Discard message, send reply message.}
if header :contains "Sender" "barkley@sesta.com
   { fileinto complaints.refs # File message}