Is there any way to ask for a return receipt when sending mail through SMTPSocket ?
It’s just a header, so yes.
Note that just because you ask for one doesn’t mean one will be sent. Users can opt-out of sending receipts.
Many advertisers add an image to their emails whose URL includes a parameter which indicates the user. That way, if the user views, you have another shot at knowing.
Superb. Thank you Greg.
and for server delivery receipt ?
It gives me so much joy when Mail asks to connect to an advertiser server on port 80 and I slam on that big ol’ deny button.
(via Little Snitch)
I will use the Return Receipt for the download instructions I send to customers. That will be another element as proof of delivery.