Read receipt requested but I'd like to know who sends it before sending receipt.

Question

I often get emails which apparently have requested a read receipt as I am always asked for my SMTP password, which I decline every time. My question is, Can I discover who is requesting the receipts so I can acknowledge them or put them on my permanent junk filter?
Thanks.

Answer 1

Oops, sorry, that was me. (Probably not, but I do request read requests on important messages.)
Read receipts should not be triggered until you open a message, or if you use the default setting of having the message marked read when you preview it. So you should be able to tell which message is associated with the receipt.
(Actually, based on my experience with Outlook, a "didn't read" receipt may be triggered by deleting a message without reading it or moving it to a folder without first marking it read.)
You can create a Message Filter to detect and tag messages with a receipt request. I only tested this on a single message, so it probably requires some refinement.
(1) Create a new Receipt tag
"3-bar menu" > Message > Tag > Manage Tags...
Click Add, then type or paste Receipt, then choose a color. I picked magenta.
(2) Create a new Message Filter
For easier entry, select and copy this text: Disposition-Notification-To
"3-bar menu" > Message Filters > New...
Click New, and name the rule something like: Read Receipt
Click the Subject button and assuming the list does not already show '''Disposition-Notification-To''', choose Customize...
Type or paste Disposition-Notification-To and click Add then OK.
Back in the Filter Rules dialog, change from Customize to Disposition-Notification-To, keep contains on the next button, and type a @ in the text box to the right. This should match any message with a read receipt request.
In the lower section, choose Tag Message and then Receipt. Click OK to save your rule.
Back in the Message Filters dialog, you can click the Run Now button to test it, assuming you have a message in the Inbox with a read receipt requested.
Once you are confident that the correct messages are tagged, you could do something more aggressive with your rule...