I've been using Emacs for email for a couple of years now. Not for everything, for now my personal email is still Gmail but work is sent and read through Emacs. I'm currently using mu4e and while it has a few quirks and limitations, I like it very much. You can take a look on how I configure and use it here.
The other day I saw this thread on Emacs about a new package - mu4e-conversation.
A couple of days ago I wrote about on my lab grading workflow. In the post I mentioned that I used Emacs to easily navigate between student folders and files so I can actually look at their work in addition to their programs output and test results.
The key is a combination of dired and ag, Emacs's interface to the Silver Searcher which is something like a recursive code grep on steroids.
I've been holding off on doing a Magit video for a while. Mostly because I wasn't using it exclusively and also because there are already a number of good Magit videos and resources out there.
What changed? Along with the new version of Magin, Jonas Bernoulli wrote up a walkthrough of the Magit interface. For whatever reason, it all finally clicked.
In spite of what the documentation says, Magit is not an interface for git.
The other day I discovered auto-yasnippet, another great package by Oleh Krehel or abo-abo.
It looks like it's going to be a great way to solve a particular problem that come up now and again.
There are plenty of times when I want to create a number of similar but slightly different blocks of text. The example on the project site is:
You could use multiple cursors, a macro, or other methods to put in the common text but you still have to deal with the parts of each line that are unique, the red, green, and blue.