I use Outlook 2010 and previously used Outlook 2003. Both versions allow Tracking Options for mail sent. Under Mail "Options" scroll down to "Tracking" and check the options you want. You may request a "delivery receipt" as well as a "read receipt"...but I urge caution when using these options. Not only do some servers refuse them, but they're not a popular tool with many recipients. Further, if your system should become infected with some em generating problem and you've opted for these email notifications, every piece of em sent from your system will flood other systems with your requests...as well as returning innumerable notices to you. So...a word to the wise...consider the down side of this Tracking option before you opt for it.

Anne

There is or was a third party free program that did that. However if the recipient knows how to do it they can go in the back door and read the message and you will be none the wiser.

I had an irritating lady who always did that to me, I would go in the back door then answer her emails and she never asked how I did it. I do not like being tracked.

As Anne notes it is in Outlook but that is a business program and for many it is necessary to know when the message has been seen to protect themselves.