Script - Move Infected Emails to Quarantine and Notify Users

The following script will do the following: 

Parse email headers from ClamScan Results
Move infected email to $QUARANTINE folder
Construct email messages
Email the users who has any infected emails in their mailbox

#!/bin/bash

ADMIN="admin@domain.com" # Admin email

QUARANTINE="/quarantine/directory/" # Quarantine folder with trailing slash

HEADER="The emails listed has been moved to quarantine and will be deleted after 30 days. If you have any concerns, please contact the server administrator" 

FOOTER="This is an automated email through ClamScan results, please find the script details at 'https://wiki.twcloud.tech/books/linux/page/script---move-infected-emails-to-quarantine-and-notify-users'"

# Getting email information

[ -z "$1" ] && echo "File parameter missing" && exit 1

[ ! -f "$1" ] && echo "File not found / not a regular file" && exit 1

declare -A emails

while read i; do

 file=`echo "$i" | sed -e 's/\:\ .*FOUND//'`

 if [ ! -f "$file" ]; then

 continue

 fi

 infection=`echo "$i" | sed -n 's/\:\ .*FOUND//'`

 to=`cat "$file" | grep -m 1 "^Envelope-to\:\s\+" | sed 's/Envelope-to\:\ //' | grep -EiEio '\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b'`

 # Try find To: header if Envelope-to: not found

 [[ -z "$to" ]] && to=`cat "$file" | grep -m 1 "^To\:\s\+" | sed 's/To\:\ //' | grep -EiEio '\b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b'`

 from=`cat "$file" | grep -m 1 "^From\:\s\+" | sed 's/From\:\ //'`

 d=`cat "$file" | grep -m 1 "^Delivery-date\:\s\+" | sed 's/Delivery-date\:\ //'`

 subject=`cat "$file" | grep -m 1 "^Subject\:\s\+" | sed 's/Subject\:\ //'`

 # Send empty "$to" to admin

 [[ -z "$to" ]] && to="$ADMIN"

 # Construct email message

 [[ -z "${emails[$to]}" ]] && emails[$to]="$HEADER"

 emails[$to]="${emails[$to]}\n\nFrom: $from\nDate: $d\nSubject: $subject"

 # Move emails to quarantine

 mv "$file" "$QUARANTINE"

done < "$1"

# Notify email users that the emails are sent to quarantine

for k in "${!emails[@]}"; do

 echo -e "${emails[$k]}\n----------\n$FOOTER" | mail -s "Infected emails quarantined" -c "$ADMIN" $k

done