In the welcome center under office software I decided to try Evolution Email but when I clicked on install I received message that package doesn’t exist?
Thanks for the feedback. Confirmed missing here in 16.04 Alpha 1. That makes 2 packages that’s missing archives for Xenial at the moment.
It could just be temporary, but I’ll inform @wimpy.
I also found that all the programs/packages that had require/work best with indications enabled in MATE tweak didn’t install in Welcome yesterday evening when I did bit of exploring, but can’t remember names. Found some great new stuff to test trough 
PS I prefer the “older” look of Welcome screen, when MATE sign change directions randomly and move around a lot more then those little circles now that remind me of some flakes, it feels a bit to much…
Those little flakes are actually a one-off since there’s an event coming up (or had passed), but it probably makes sense to “celebrate” on the day, I’ll see about changing that.
Thanks for explanation @lah7. It makes sense, if it’s only temporary or when something new happens but I personally wouldn’t want it all the time and I prefer how it looked before.
@Wimpy if it helps under details for Evolution Mail it says Package evolution-mapi isn’t available
I found another two with message Package does not exist under accessories Recent Notifications (Package indicator-notifications isn’t available) and under Sound and Video Ambient Noise (Package anoise isn’t available).
Thanks for the feedback @ele. It could also be that the packages for some software are not built (or currently broken) for Xenial at the moment … so they’ll work auto-magically in a few weeks by refreshing apt.
Some errors are our fault (typos…!) - Keep an eye out for updates to ubuntu-mate-welcome in the upcoming weeks for fixes! 
Open Terminal and then execute the following command:
sudo apt-get clean
sudo apt-get autoclean
sudo apt-get update
sudo apt-get install evolution
It's working for me.
Hi nahrafqifahs, welcome the the forums Thanks for the suggestion, but 16.04 testing cycle is over. We have moved on to 16.10 testing and I am closing this thread.