How to create a custom workflow to send a mail with read receipt.

Hi all,

I want to write a custom work flow to send mail to multiple opportunity at a time,

Each mail i send must have an read receipt added to it.

By default in CRM the read receipt is disabled . how to activate that read receipt while sending a mail in crm 2015(On premises).

please let me know how to proceed.

Thanks and Regards,

Leonard Francis