Per avvisare gli utenti email che lo spazio a disposizione per l'account di posta elettronica sta per essere superato ho reperito il seguente script che controlla lo spazio delle caselle email ed invia all'utente un avviso

http://forum.parallels.com/showthread.php?t=106635

Come devo modificare lo script per fare in modo che i messaggi vengono inviati solo qualora $HARDQUOTA è + grande di 0 ?

inoltre lo script mi dà il seguente errore: mail: invalid option -- a

codice:
#! /bin/sh
# Mail quota reaching it's limit e-mail notification
# script for Plesk 9.3+ / Plesk 10 & Qmail
# Modified by "Scy" from the original script
# provided by "azur99" in Plesk forum:
# http://forum.parallels.com/showthread.php?t=71666
#setenv QMAILUSER 'do-not-reply'
MAILROOT=/var/qmail/mailnames
cd $MAILROOT > /dev/null
for DIR in *.*;do
        cd $MAILROOT/$DIR
        for MAILBOX in * ;do
                if [ -d $MAILBOX ]
                        then

                        # look for specific mailbox quota file and set mailbox softquota
                        QUOTAFILE=$MAILROOT/$DIR/$MAILBOX/Maildir/maildirsize
			
			# Fetching mailbox quota size in bytes
			HARDQUOTA=$((`head -1 $QUOTAFILE | cut -d S -f1`))
			HARDQUOTA=$(($HARDQUOTA+4096))		

			# Fetching space used by mailbox in bytes
			MBOXSPACE=$((`tail -n +2 $QUOTAFILE | cut -c1-12 | paste -sd+|bc`))

			# Calculate the quota limit required for mail warning (95% for default)
			SOFTQUOTA=$((95 * $HARDQUOTA / 100))

			# Calculate mailbox usage percentage (with two decimals)
			MBOXPERCENT=$(echo "scale=2; $MBOXSPACE*100/$HARDQUOTA" | bc)

			# Check if the mailbox is full enough for warning, and if, send the warning mail
            if [ $HARDQUOTA -gt 0 -a $MBOXSPACE -gt $SOFTQUOTA ]; then
			
				# Let's generate the values in megabytes (with two decimals)
				HARDQUOTA=$(echo "scale=2; $HARDQUOTA/1048576" | bc)
				if [ "$(echo $HARDQUOTA | cut -c1)" = "." ] ; then HARDQUOTA="0"$HARDQUOTA
				fi
				MBOXSPACE=$(echo "scale=2; $MBOXSPACE/1048576" | bc)
				if [ "$(echo $MBOXSPACE | cut -c1)" = "." ] ; then MBOXSPACE="0"$MBOXSPACE
				fi
			
mail -s "E-mail quota warning!" $MAILBOX@$DIR -a "Content-Type: text/plain; charset=ISO-8859-1" << EOF
Dear mailbox user,

Your e-mail '$MAILBOX@$DIR' is about to reach its maximum quota and is already using $MBOXSPACE MB ($MBOXPERCENT%) out of the maximum quota $HARDQUOTA MB.

We would kindly suggest you to delete some older messages and purge them to free some disk space for mailbox. In case the quota limit is reached, you won't be able to receive any new messages and the sender will receive  'mail quota exceeded' notifications.

The other option is to configure POP3 mail client (e.g. Microsoft Outlook, Mozilla Thunderbird or Mac Mail) that would empty the server mailbox every time the mail account is read and move the old mail to local disk of your own computer.

PS. This is an automated message and should not be replied. If you require any assistance, please contact to your mail server provider.
EOF

			fi


				fi
        done;

done;

Grazie per un consiglio