Periodic error messages with Postfix - unsupported: -bh

[Chris Hastie]

Hi

A couple of days ago I installed Postfix on a new FreeBSD 5.1 system and 
since then the daily reporting run produces this:

| Oct  6 03:01:01 ash postfix/sendmail [1135]: fatal: unsupported: -bh

I presume something somewhere is calling sendmail with the -bh flag. Any 
clues as to how to change this, and what to change it to?
-- 
Chris Hastie