There isn't a log that I know of, but I have made a suggestion that was received well by the dev team. On the options page there is an option that says "Maximum email alerts to send per hour" and its defaulted at 0 which means 'as many times as an event happens" which can be a trifle annoying depending on how popular you are. :) The suggestion was made on the forums here to have an option to get those once a day, and I believe I added that it would be great if we got a number of how many logins were blocked, etc. I don't know the details of what can or can't be done, if or when the suggestion is being implemented, etc but I can tell you that we take every suggestion seriously. Our community helps us design the product and make it the best it can be.
Does this help answer your question?
tim