I seem to recall a conversation about substituting postfix for sendmail for sending email from bro/broctl, but now I can't find it. Is there anything special that needed to be done to use postfix instead, or was sendmail a hard requirement? I'm getting some pushback on using sendmail as listed in the Bro docs as the system admins prefer to use postfix.
Bro does not require sendmail, it just requires the 'sendmail' binary. Postfix (and every other smtp server) provides a compatible binary.