#!/usr/bin/env bash
#
# Extracts the IP address from the first 'Received:' header
dir="$1"

if [ -z $dir ]; then
	echo "Usage: $(basename $0) <path-to-mailbox>"
	exit 1
fi
for spammail in $(find "$dir" -type f); do grep '^Received:' $spammail | tail -1; done | grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'