1)My main script Calls a function IsDomain to check whether the domain is valid or not

PROD>/appl/retek/mpscripts/cat mg3TRn01
#!/bin/ksh
#
# Standard Header Files
#
#
. ${0%${0##*/}}UKMPFunctionLibrary.test
#
# START
#
ScriptStart
#
# Check that domain exists.Print & Commit the ASAP queue
#
IsDomain $SPDOM
ScriptEnd
#
# END
#

2) My global function library UKMPFunctionLibrary.test has the below functions defined

#
# Set Schedular Envronment Variables
#
. ${0%${0##*/}}UKMPEnv
THISFILE=${0##*/}
OVWFILE=$LOGS/mps_ovw.log
LOGFILE=$LOGS/$THISFILE.log.$(date "+%y%m%d%H%M%S")
TMPFILE=$TEMP/$THISFILE.tmp
WARNINGS=false
#
# Standrad log function
#
Log() {
case $2 in
0) LOGMSG=INFO;;
1) LOGMSG=WARNING;WARNINGS=true;;
2) LOGMSG=ERROR;;
*) echo $1 >>$LOGFILE; return;;
esac
echo $(date +"%T")' - '$LOGMSG' - '$1>>$LOGFILE;
echo $THISFILE' - '$(date +"%T")' - '$LOGMSG' - '$1
>>$OVWFILE
}
#
# Standard Mailing {Parameters 1 - Subject 2 - List of mail ids}
#
SendMail()
{
if [ $# -eq 2 ];then
echo " "|mail -s "$1" "$2";return $?
elif [ $# -eq 3 ];then
cat $3|mail -s "$1" "$2";return $?
else
return 2
fi
}
#
# Exit Codes {0 - Success; 1 - Warning; 2 - Failure}
#
Exit() {
case $1 in
0) Log 'END - SUCCESS' 0;exit 0;;
1) Log 'END - SUCCESS WITH WARNINGS' 1;exit 1;;
2) Log 'END - FAIL' 2;
MAILLIST="shilpi.sood@in.tesco.com";
SUBJECT="ALERT - The job $THISFILE has failed @
$(date)!Please Check";
SendMail "$SUBJECT" "$MAILLIST";
exit 2;;
*) Log 'END - ERROR' 2;exit 2;;
esac
}
#
# Standard Log File Heading
#
ScriptStart() {
echo $(date +"%Y%b%d")>>$OVWFILE
echo $(date +"%Y%b%d")>$LOGFILE
Log "START" 0
}
#
# Standard Log File End
#
ScriptEnd() {
Log 'END' 0
if [ $WARNINGS == 'true' ];then
Log 'SUCCESS WITH WARNING' 0;exit 0
else
Log 'SUCCESS' 0;exit 0
fi
}
#
# To check the existance of a domain {Parameter 1 - Domain
# Path}
#
IsDomain() {
checkDomain -d $1 -type simple>>$LOGFILE
if [ $? -ne 0 ];then
Log "Domain $1 does not exist" 2;Exit 2
fi
}

3) On failure the script is not returning the correct return code due to which we are facing issues.
In the global function Exit() can we not call the global function Sendmail()?
How can I edit the code so that the correct return code is passed from the script on failure?