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 enable-delivery-status-notification 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 Delivery-receipt-to: header.

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 receipt.

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.