unable to send mail

UNIX AIX
1

hi,

I have tried this code to send mail.Its not giving me error but I am not receiving mail also.

#!/bin/ksh

echo  "The first mail"  >msg

cnt=`cat /dir1/msg | wc -l`

if [ $cnt -ne '0' ]
  then
      mail -s "Hello" abc.xyz@domain.com < msg
fi

I have also tried with the command

mailx -s "hello" abc.xyz@domain.com

even this is not working.

Do any one have any idea

Thanks