Email Quota Check Alarm

here is a shell script the is used to notify the postmaster and/or the user on email quota percentage.
it can be used in cron job in cpanel iwth the following command:

sh "your shell script path and name"

you can append this to the end of you command ">/dev/null 2>&1" to avoid sending an email the postmaster every job; in this case the command will look like:

sh "your shell script path and name" >/dev/null 2>&1

the shell script:

#!/bin/sh
# checkmailquota for cPanel
# Scot Hacker, shackerREMOVETHIS@birdhouse.org
# v. 1.4, Oct. 1, 2005
# This script sends warning messages to owners of near-quota mailboxes
# and a separate summary message to postmaster or other address.
# Must be run as root, or via root crontab.
#   Limitations:
# - Main account holders cannot have mailbox quotas in cPanel, so this script can't check for them
# - Notifications cannot be sent to parent account holders.
# - If a user has  set their quota to "unlimited," nothing will be reported
# History:
# 1.4: Only sends warning messages if quota usage is less than 100% (so root doesn't get bounce messages)
# 1.3: Tallies # of mailboxes checked and reports back
# 1.2: Now handles domains with missing quota files
# 1.1 : Summary notice to postmaster now optional; checks whether boxtrapper is installed and skips its dirs.
#   Installation:
# - Rename to checkmailquota and place in root's  path (/root/scripts is good)
# - chmod 744 checkmailquota
# - Edit the four vars below and the message text to taste.
# - Create /etc/cron.d/mailquotacheck with the following two lines (to check 4x daily):
# SHELL=/bin/sh
# 15 */4 * * * root /bin/sh /root/scripts/checkmailquota
# Quota percent threshold (expressed as integer between 1 & 100)
quota=70
# Should script send quota warning mail to users, or just to postmaster?
# Set to 0 to skip sending mail to users
# 1 is highly recommended, but test with 0 first
enable_user_warnings=0
# Should script send overage summaries to postmaster?
enable_postmaster_notice=1
# Postmaster email
postmaster="youremail@yourcompany.domain"
# Define user alert mail text first, as function to be called later.
function send_user_mail(){
user_alert_text=""
# Send the message
# For test run, uncomment the next line and comment out the following
#echo "$user_alert_text" | /bin/mail -s "Warning: Mailbox nearing quota" $postmaster
echo "$user_alert_text" | /bin/mail -s "Warning: Mailbox nearing quota" $thispop@$thisdomain
echo "Sent warning message to $thispop@$thisdomain"

}
# Do not edit below this line
##############
# Zero out temp file from last script run
echo "" > /tmp/mail_quota
# Initialize mailbox counter
num_boxes=0
# Main account loop
echo
echo "Listing POP boxes using more than $quota% of quota."
for account in /home/*; do
 account=$(echo $account | sed s#.*/##)
 echo
 echo
 echo "============================================="
 echo
 echo "User: $account"
 for domain in /home/$account/etc/*; do
  # Make sure we only read in directories, not other files
  if [ -d $domain ]; then
   thisdomain=$(echo $domain | sed s#.*/##)
   
   # Skip this entire block if "boxtrapper" directory encountered - not quota-related
   if [ $thisdomain != "boxtrapper" ]; then
    echo ""
    echo "$thisdomain:"
    echo -e "%\tOver\tMailbox"
    echo
           # Read lines from  this domain's quota file, if  present
    # (User may have manually removed their quota file)
    if [ ! -f /home/$account/etc/$thisdomain/quota ]; then
     echo "This domain has no quota file!"
    else
     exec < /home/$account/etc/$thisdomain/quota
    fi
    while read mailbox
    do
     # Re-set $over marker
     over=""
     thispop=$(echo $mailbox | sed s#:.*##)
     thisquota=$(echo $mailbox | sed s#^.*:##)
     # Get actual usage for this mailbox
     # -b shows bytes rather than k.
     usage=$(/usr/bin/du -b -s /home/$account/mail/$thisdomain/$thispop)
     # Output needs to be trimmed
     usage=$(echo $usage | sed s#\ .*##)
     # Do the math -- divide usage by quota to get percentage
     percent=$(echo "scale=2; $usage/$thisquota*100" | /usr/bin/bc)
     # Convert floating point to integer
     percent=$(echo $percent | /usr/bin/bc -l | awk -F '.' '{ print $1; exit; }')
     # Is this mailbox over quota?
     # Only send warning message if quota usage is under 100%; 
     # otherwise messages are never delivered, and also bounce back to root.
     if [ $percent -gt $quota -a $percent -lt 100 ]; then
      over="X"

      # Send alert mail to user via function above, if enabled
      if [ $enable_user_warnings == "1" ]; then
       send_user_mail $thispop $thisdomain $percent
      fi
     fi
     # Record overage for postmaster even though we're not alerting user above
     # (Here we don't care if account is at 100%)
     if [ $percent -gt $quota ]; then
      # Append this overage record to a text file we'll suck back in later
      # and mail to postmaster.
      echo "$percent% :: $thispop@$thisdomain" >> /tmp/mail_quota
     fi
     # Report to shell
     echo -e "$percent%\t$over\t$thispop@$thisdomain"
     # Increment counter so we know how many mailboxes were checked
     # Note: Count may not be entirely accurate if user has deleted
     # quota file, or if user is using main account for mail rather
     # than standard cpanel mailbox.
     let "num_boxes += 1"     
    done
   fi
  fi
 done
done
# Report number of boxes checked to the shell
echo
echo "~~~~~~~~~~~~~~~~~~~~~~~~~~~"
echo "$num_boxes mailboxes checked"
echo
# Also append mailbox count to summary to be mailed
echo "
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
$num_boxes mailboxes checked
" >> /tmp/mail_quota
# Send summary to postmaster
if [ $enable_postmaster_notice == "1" ]; then
 postmaster_msg=$(/bin/cat /tmp/mail_quota)
 echo "$postmaster_msg" | /bin/mail -s "Customer mailboxes near quota" $postmaster
fi
#END

don't forget to edit your email in the red highlighted field if you want to receive a cron job notification as an administrator.


Many thanks to the script developer:

Scot Hacker