Is there a way to ask for delivery receipt (Return-Receipt-To) using TIdMessage?

I have an application that sends emails via SMTP, I'm using TIdMessage but it seems like only read receipt is working (ReceiptRecipient property).

I'm aware that delivery receipt isn't supported by all email servers, but if the user already knows it works using their email client (for example, they see it works on MS Outlook) they want it to work with my SMTP email application too.

CodePudding user response：

The TIdMessage.ReceiptRecipient property sets both Disposition-Notification-To (read receipt) and Return-Receipt-To (delivery receipt) email headers.

If you don't want Disposition-Notification-To set, then leave the TIdMessage.ReceiptRecipient property blank, and then use the TIdMessage.ExtraHeaders property to set just the Return-Receipt-To header.