Add a 'Read Receipt' which the person receiving the email can choose to send or not.
A question could be displayed when the email is opened which says:
The sender of this email has requested a 'Read Receipt' do you wish to send one? Click Yes or No.
Then if they don't want to send a 'Read Receipt' just click 'No'.
Add a 'Read Receipt' which the person receiving the email can choose to send or not.
A question could be displayed when the email is opened which says:
The sender of this email has requested a 'Read Receipt' do you wish to send one? Click Yes or No.
Then if they don't want to send a 'Read Receipt' just click 'No'.