Nope, that doesn't work either, but instead fills the log with different errors:
Aug 29 20:34:39 Daves-iBook sendmail[854]: g7U0Yd4U000854: SYSERR(dave): collect: Cannot write ./dfg7U0Yd4U000854 (bfcommit, uid=501, gid=25): Permission denied
Aug 29 20:34:39 Daves-iBook sendmail[854]...