I've started a small monthly e-mail newsletter for our B & B to about 90 or so of our previous customers.
Take a look here http://munrosbb.cmail3.com/e/425234/l/
The thing is, does CM take into account recipients who don't actually open e-mails but read them in the preview pane? I do this with quite alot of my mail.
Out of the 90 sent out only 38 have opened according to CM - remember, these aren't cold mails. These people have stayed with us and seem to have enjoyed it.
Munro's B & B
Isle of Bute
You can read about how we calculate open rates here: