Nikki Peterson" wrote in said:
...
Read Receipts are at the discretion of the receiver. This means that
If you send me an email and request a read receipt, I have my email
client set up to let me know that you are requesting a read receipt.
I then have the choice to either send you one, or not.
The best you can really do is also request a "Delivery Reciept". This
will trip the receiving mail system to send you an acknowledgement
that your email has been accepted or denied. If it is accepted, you
will know that the email has reached your requested mailbox
destination and was delivered to the recipient.
Actually all a delivery receipt says is that the receiving mail host
got your e-mail. It does NOT indicate that the e-mail got delivered to
anyone's mailbox. For example, the mail host may accept the e-mail and
even know it was deliverable (because the recipient's mailbox exists)
but then slams into a blacklist that auto-deletes the message so it
never arrives in the recipient's mailbox. A delivery receipt says
nothing except that the receiving mail host got it.
Most mail servers never bother to send back delivery receipts. Why?
Because they already send back negative feedback in the form of NDRs
(non-delivery reports). Not getting an NDR means the receiving mail
host accepted your message. They see no need to send back positive
feedback when the lack of negative feedback already provides that
information. Don't expect many mail hosts to bother sending you
anything back for a delivery receipt request.
A delivery receipt says absolutely nothing about whether an e-mail ever
reached the recipient's mailbox. Few mail hosts bother to send back a
delivery receipt.