#!/bin/bash
## sillymail
## simple 'telnet' email client
##	exercise in bash, except, smtp, ...
## 

# requires 	expect
#			mimencode (for attachments), .deb=metamail
#
# Koen Noens, november 2008
# This is free software under the terms and conditions of GPL v3

## TODO : 	mechanism to take command line arguments
#			handle script errors
#			modify expect script so that it not only handles SMTP "250 OK"
#

# param
SERVER="$1"
PORT=25
RELAY="$SERVER $PORT"

## params for attachment
withAttach="n"
MIME="MIME-Version: 1.0 "
ENCODING="Content-transfer-encoding: base64; "
CONTENTTYPE="Content-Type: multipart/mixed; "
BOUNDARY="000MultipartBoundary000MultipartBoundary0000"
ATTACH_TYPE="Content-Type: application/octet-stream; "
ATTACH_NAME=""
ATT_ENCODED=""

BODY=$(mktemp)
ATT_ENCODED=$(mktemp)

## User Interface
echo;
echo -n "HELO: ";	read HELO;
echo -n "mail from: ";	read FROM;
echo -n "mail to:  ";	read TO;
echo -n "subject:  ";	read SUBJ;
echo -n "with attachment [yn]? "; read withAttach;

if [ "$SERVER" = "" ]; then
	echo -n "mail server: " ; read SERVER
fi

usage (){
	echo; echo "$0 server"
	echo "where server is the fqdn of a mail server"
}


getAttachment () {
        echo; echo -n "attachment: attach file (path): " ; read ATTACH;
        if [ -f $ATTACH ]; then
                echo  "encoding and attaching $ATTACH .... "
                mimencode $ATTACH -o $ATT_ENCODED
				ATTACH_NAME=$(basename $ATTACH)
        else
                echo "$ATTACH : file not found, aborting"
                exit 1;
        fi
}


## create mail msg
echo "write message. Ctrl+D when Done"; echo
(cat > $BODY)

if [ "$withAttach" = "y" ]; then

	getAttachment

	#modify body to multi-part
	BODYTEMP=$(mktemp)
	cat $BODY > $BODYTEMP; rm $BODY
	BODY=$(mktemp)
	
	echo "$MIME" >> $BODY
	echo -e "$CONTENTTYPE boundary=\\\"$BOUNDARY\\\"" >> $BODY


	#From, to, can be repeated here for mail client display
	#CC and BCC can be put here if the have a RCPT TO in envelop

	echo -e "Subject: $SUBJ \n\n"  >> $BODY  

	#subject line marks the end of the extra headers in DATA
	#newlines are significant in boundaries, don't change.

	### text part ###
	echo -e "\n--$BOUNDARY\n\n" >> $BODY
	cat $BODYTEMP >> $BODY

     	### attachment ###	
	echo -e "\n--$BOUNDARY" >> $BODY
	echo "$ENCODING" >> $BODY
	echo -e "$ATTACH_TYPE name=$ATTACH_NAME \n" >> $BODY
	cat $ATT_ENCODED >> $BODY
	
	### body end ###
	echo -e "\n--$BOUNDARY--\n" >> $BODY

		# # # #
		# Attachements also require additional mail headers
		# so there's another withAttach==y section in
		# the protocol section of this script
		# # # #
fi		

## do protocol with expect
expect <<EOF
spawn telnet $RELAY
expect "220*"

## ENVELOPE 
send "HELO $HELO \r"
expect "250*"
send "MAIL FROM: $FROM \r"
expect "250*"
send "RCPT TO: $TO \r"
expect "250"

## BODY / MSGs
send "DATA \r"
expect "354*"
if {$withAttach != y} {send "Subject: $SUBJ\r\r"}
send "$(cat $BODY) \r\r.\r"
expect "250*"
send "quit \r"
expect "250*"
EOF


## cleanup
rm $BODY $ATT_ENCODED $BODYTEMP