I've noticed receipts going out with subjects starting "Not read:" in response to junk e-mails that were deleted without being read. I'm sure the e-mail addresses they were sent to were forged, so the recipient of the receipt didn't ask for them in the first place. This is just like receiving those "undeliverable" messages from those mail servers set up to send e-mail to the forged from address on all those junk e-mails or those antispam filters that send nasty responses to the forged from address that the spam was not wanted. I hate those!
I looked at the content filter and its options, but didn't find anything I thought seemed perfect for this job. I want to block only the "Not read:" receipts from going out, but not the read receipts or delivery receipts or any incoming mail. I don't necessarily want to assume nobody will ever send a legit e-mail with "Not read:" in the subject. I know about the options in Outlook, but I can't tell everyone to turn them off.
Any suggestions?