Send an email sometime on the weekend, and by the time Monday rolls around, it will be buried under a pile of other emails crowding your recipient's inbox. But what if you don't have time to send the email at just the right moment for it to be seen? If you're using Gmail, Right Inbox can do that for you. This service ($5/month or $39/year, free feature-limited demo) can also track sent emails and report when the recipient opened them, and remind you about emails that haven't received a reply so you can follow up.

Right Inbox comes as a browser add-on for Firefox, Google Chrome, and Safari. It blends into Gmail so seamlessly you may have trouble finding it at first. There is no control panel, and nothing to configure. Unlike ActiveInbox, it doesn't create lots of new labels within Gmail. It simply shows up as a few new buttons in the email composition screen, and one new button in the message reading screen.

The Remind Me button is the one that also shows up in the message reading screen: You can use it to snooze threads that don't require immediate action or are awaiting other information, and have them come back to your inbox when the time is right. This is also the only part of Right Inbox that gave me any trouble: The button wouldn't always show up, and I had to refresh Chrome every now and then to get it to display.

Right Inbox gets a lot right: The interface is simple and well-integrated, and the price is reasonable. If you're a Gmail or Google Apps user looking for an email scheduling and tracking solution, you should try it out.

Note: The Download button takes you to the vendor's site, where you can download use latest version of the software on your Gmail or Google Apps account running in a supported browser.

—Erez Zukerman