Locating Corporate Email Addresses

One of the most difficult pieces of information to locate can be an executive's email address.  Whether you're interviewing for a job, networking, or want to learn more about a particular industry, having access to email addresses is critical to establishing contact.  Yet it can be an elusive piece of information to locate.  Recently, I came across a blog post that delves into strategies to locate this information:
http://www.fsoresearch.ca/tips-and-tricks-for-finding-email-addresses/