To send mail notification to your clients you should use your domian related email id, kindly note that gmail, yahoo or outlook mail id wont work.
To create your domian realated id , login to kharedi.in .
Click on “My online Store” Menu >> Click on Active Plan >> and under “Quick Create Email Account” enter email id and password and click create.
Done! You can view your mail by going to www.yourdomain.com/webmail using your email id and password.
Now configure same email id in you website admin to send email notification on various clients activity.
Go to website admin. eg. www.yourwebsite.com/admin
System >> Settings >> Edit your Store>> in geneal tab under email field enter your newly created email id and save.
Then Go to System >> User>> User >> edit Administration and enter your newly created email id and save.