escape "^From "

[LuKreme]

What controls escaping "From " in the body of a mail message if it's  
at the start of a line? Since I've switched everyone over to Maildir,  
it seems silly to do this anymore, but I can't find the setting.  In  
fact, I'm not even sure it's in postfix at all.

RTFM replies preferred, just say with FM to R, please.
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