I don't ever acknolege a read receipt request for emails I receive. But a friend said they sent me an email with read receipt and it was acknowledged. How could this happen?
Well this happened to me and I was not happy. I use Outlook and whenever I get a pop-up saying the sender requested a read receipt I respond "NO". Usually it is someone phishing to see it the email address is active and wants to sell me something or making sure I received the email about the party this weekend.
When this happens I never acknowledge receipt or read. As it turns out the email that was sent I opened on my iPhone. There is a setting in iPhone Settings, Messages, Read Receipt that was turned on. I immediately turned it off. I was surprised that this option would default to on, but it does.
So my advice is to turn this setting OFF.
I also investigated how different email services, as well as different email applications handle Receipt and READ requests. They all have different options and abilities. So my suggestions is to investigate your email system and device to make sure receipt and read requests are turned OFF. Also if you send an email requesting a receipt or read acknowledgement don't depend on a response to know it your email was actually received or read.