We've all been stuck with the same email problem: You send off an email and then wonder what happens with it. Did it ever reach its destination and get read? If you sent links in the email, what happened with them--did they get clicked? For Microsoft Outlook users, Zendio ($10/month, 30-day free trial) has the answers. This Outlook add-in tracks what happens to mail after you send it, and reports back to you on the results.

Zendio also lets you attach different signatures to different emails, something that is very time-consuming and kludgey to normally do inside Outlook. And because it integrates directly into Outlook, Zendio is exceptionally easy to use.

Now the bad part--Zendio's price. At $10 a month, this is an expensive piece of software. It'll be worth your while only if you need it for business reasons. If you do, however, you'll find it quite useful.

--Preston Gralla