I've used MailTrack for ages, both as Paid for and Free. As I deal with the general public, and a large part of my job is to get information, Mailtrack is invaluable. I can see when emails have or haven't been opened so can keep an eye if I haven't heard from clients rather than pester them. On the free side, I use it for all my personal emails to I know if it's been received. No more of the "I didn't get your email" excuse!!! For me the only disadvantage of the free version is that it shows your email is being tracked, not much of a problem considering its free! MailTrack is an essential tool in my day to day life and I wouldn't be without it. I have tried others, but I always come back - Keep it up!!!