Sieve vacation not getting enough headers "no known (envelope) recipient address found in message headers"

[Marc Roos]

I am getting these errors[1]. With fairly default setup where sendmail 
is delivering mail via lmtp. Adding these, do not seem to make a 
difference. Should I add something to the sendmail configuration?

  sieve_vacation_dont_check_recipient = no
  sieve_vacation_use_original_recipient = no

[1]
discarding vacation response for implicitly delivered message; no known 
(envelope) recipient address found in message headers