There are a lot of email tracking tools out there, but I really, really love the user interface of FollowUp.cc. It's a great tool to use in Gmail and I like being able to track all emails. Review collected by and hosted on G2.com.
I used to get it for free, now there is a cost. That is really all that I dislike. I haven't run into any problems, and the user interface is super easy to use. Review collected by and hosted on G2.com.
I appreciate how quickly I can send an email to followup and have it read...so if I need to take care of something in a week, instead of having an email sitting unread for the week, i can just receive it again in 1 week...knowing I won't miss it or it getting buried whlie also being able ot postpone it being unread Review collected by and hosted on G2.com.
I haven't really had any issues with it, but I haven't found any practical use for the toolbox in Gmail itself. Review collected by and hosted on G2.com.