I also found it annoying, however, I can understand why employers or supervisors use it. I worked for the US Govt. many years and saw how employees ignored directives and directions. Supervisors want to hold their underlings accountable and receipts are one way of doing that.
You can't really do that. There is no universal read-receipt out there, it's buggy at best and only works between closed-systems like one you may use at work where everyone uses the same email client on the same network.
Understood, but if employees are ignoring their superiors and not getting the job done they should be canned. Period.
I agree, but if you knew how much trouble and how much paper work is involved to fire someone who is fully vetted in the US Civil Service, you can understand why supervisors try to use other measures.