Automatically Associating Emails With opportunity

Hi All,

I have use case as below:

Suppose if any opportunity is created/ updated then we send email to user via process definitions send message functionality, If the customer/user  replies/answers to that email then it should link to that opportunity  Emails subpanel.

Can anyone suggest how to achieve this?

Note that:

  1. Email which we are may or may not have assigned user in CC,TO,BCC
  2. Email might be sent to group email which may not be there in any users primary email address

Please suggest asap.

Kindest Regards,

Shreya