Not strange at all. We don't have delivery receipts turned on for any message coming to our company email and I have read receipts turned off on my inbox so if you sent me a mail you would get neither type of receipt (though you may get a reply!).

We turn off all delivery receipts on our company email to stop spammers trying every name combination to find which ones are real.

I block read receipts on my inbox because I want to control if and when I reply - I don't want to feel I must reply because the person knows that I have read the mail.