Simple e-mail autoresponder which doesn't send e-mail to an address more than once.

emailresponder.sh

#!/bin/bash

/usr/bin/getmail -r /home/USER/.getmail/getmail.rc

mailpath=/home/USER/mailpath
tmpdir=$(mktemp -d)

echo "########################################################"
for i in $mailpath/new/*; do
	if [ -f $i ]; then
		echo "Reading Message $i"
		echo "########################################################"
		while read line; do   
			#echo $line
			case "$line" in
				"From: "*)
					tmpemail=$(echo "$line" | sed 's/ *(.*)//; s/>.*//; s/.*[:<] *//')
					if grep -Fxqi "$tmpemail" /home/USER/.getmail/emailresponder_list.txt
					then
					    echo "$tmpemail exists in database; fail silently. I shan't be a spammer."
					else
					    tmpfile=$(mktemp -p $tmpdir)
					    echo "Sending email to $tmpemail"
					    # so we don't send e-mail to them again.
					    echo "$tmpemail" >> /home/USER/.getmail/emailresponder_list.txt
					    # Remember to compose your e-mail FIRST, leaving the TO: line blank!
					    # this is so the multipart headers don't get overwritten by the MTA
					    /usr/sbin/sendmail -i "$tmpemail" < /home/USER/.getmail/responding_email.txt						    
					fi
				;;
			esac	
		done <$i		
	rm $i
	fi
done