Many spammers are using the free, public URL shortening services. This has led to a conclusion that it is best not to share a short URL via email since it's the method most spammers use to access your account. Not only that but you run the risk of being blocked by the email service if you repeatedly send short URLs via email. A research study conducted by the security firm Cloudmark found that only 7 percent of the short URLs from Twitter was actually from legitimate URL shortening users. Mea...