PMDF provides support for delivery receipts (a confirmation message is sent to you when your message reaches the recipient's mailbox).
Read receipts (a confirmation message is sent to you when your message is actually read by its recipient) are a matter for mail user agents (clients) that actually read the messages out of message stores, rather than mail transfer agents such as PMDF that deliver messages to message stores. PMDF passes read receipts through so that mail user agents that support read receipts may act upon them, should they want to.1
There are two separate issues concerning delivery and read receipts. First, a mechanism must exist with which to request delivery or read receipts. Your mail user agent may or may not allow you to request delivery or read receipts. Secondly, support must exist at the receiving end to recognize a request for a receipt --- a receipt request --- and generate the requested receipt. Again, PMDF provides this functionality. However, other mailers may not and thus it is not unusual for receipt requests to be ignored.
In general, delivery receipts should be requested according to the
NOTARY mechanism specified in RFC 1891. In particular, when delivering
to system mailboxes on the PMDF system or to PMDF MessageStore or PMDF
popstore accounts, only NOTARY delivery receipt requests will be
respected. For instance, to request a delivery receipt when using pine
4.44, first set the
option in the Setup Config menu; then when sending a message for which
you want a delivery receipt, after pressing Ctrl/X (to Send), turn on
the DSNOpts by pressing
D (and then optionally turn on or
off various of the notification options) before answering
Y (to actually send the message).
Some PMDF delivery routes, such as delivery to LAN based e-mail systems
such as cc:Mail, Microsoft Mail, GroupWise, or MHS based mail systems,
also support delivery receipts requested via non-standard headers. If
your user agent does not provide you a specialized way to request
delivery receipts but does allow you to add your own headers, you may
request a delivery receipt by adding a
Read receipts should be requested using the standard
Disposition-notification-to: header defined in RFC 2298.
If your user agent does not provide you a specialized way to request
read receipts but does allow you to add your own headers, you may
request a read receipt by adding such a header. For instance, pine
allows you to add any headers you want via the
customized-hdrs Setup Config option. You may hence add a
Disposition-notification-to: header to request a read
When delivering mail with a read receipt request, in some cases PMDF will convert the request into a delivery receipt request when it knows that the mail user agent to which the mail is being delivered cannot honor a read receipt request.
Never, ever request a receipt of any sort when posting a message to a mailing list. While some mailing lists properly block receipt requests, many do not. Should you accidentally request, for instance, a delivery receipt from a large mailing list, you will end up with hundreds, if not thousands, of receipts.
1 Most mail user agents which support read receipts allow the recipient to block them. This is typically the default; i.e., most mail reading programs will not generate read receipts unless the reader of the message expressly approves them.