[wlj]

Boomerang for Gmail [0] has implemented this functionality well.

I prefer it to say having an entire folder of emails I haven't received replies on as it allows me to specifically manage messages that are important enough to require a non-replied reminder.

[0] http://www.boomeranggmail.com/

[hijonathan]

Boomerang and Followup.cc are both great alternatives, and I use them too. I like the granularity, but the downside is you're sending them a copy of your email, which might contain sensitive info :\

[chimeracoder]

If you're looking for Boomerang functionality without the security/privacy implications, I wrote an open-source version that is designed to be self-hosted: https://github.com/ChimeraCoder/go-yo

It's written in Go; there's no external dependency except a service that downloads emails to a Mailbox-type directory (I recommend offlineimap).

I've been dogfooding it myself for the last few months - I haven't actually "released" it officially yet, but if anybody is interested in beta testing it, I'd love some feedback.

[chany2]

Just curious, based on your research, are people really concern about security of their confidential emails?

When do the access to better features outweight the need of security?

If you use Mailbox, they actually temporarily hold on to your rebounce emails as well. Other email apps such as Skimbox, the emails are stored in their MongoDB server. Obviously the value of this 2 applications, granted they are still alive and used by folks, then the features > security concern. Not that they are compromising your messages anyway.

I am sure different people have different priorities. Just a curious question based on your findings.

Btw I also called myself an aspiring entrepreneur in most of my email introductions. I think its just my humble way of saying I am working on it and dedicated to growing - as oppose to being too boastful when asking for advice.

Find me @ http://www.linkedin.com/in/garyyauchan/

Also love to get your feedback for Hashtags for Email @ https://news.ycombinator.com/item?id=6948659

[andy10]

I like http://toolbox.mxhero.com, It's free for unlimited messages and also does interesting things with attachments and a few other features I find useful. They also have an open source version http://sourceforge.net/projects/mxhero/?source=navbar