I have been using Zarafa/Kopano successfully for years and I think it's great.
You can get the community packages yourself here:
https://download.kopano.io/community/
And to my experience they are easy to manage.
You can also have videoconferencing, cloud etc. etc. all installed in the community edition.
Highly recommended, at least it works for me.
Hi, Kopano is simply the new name for Zarafa, which has been around for a long time.
It's zarafa++ and essentially only Kopano will be developed going forward.
Where is the bit of my posting that says that:
Zimbra gives you the community software which is the same as the paid one except it contains little features for free?
Kopano gives you the entire stack out of the main branch and if you want the production releases you call them up?
The net result for an unpaid user is a tradeoff of features vs releases.
For a paid user the net result is the same other than perhaps you choose the one that looks best for you?
At the end of the day that's the summary.
You do not need all the advanced features by the look of it therefore you can stay with Zimbra.
I can't as I need the full product.
Leaving banks aside software companies like car companies make products that people want to buy.
Diesel cars are polluting? Yes they are but people buy them so they make them.
Ubuntu lts isn't supported? Yes but people or companies run it therefore software companies make software for it!
Electric cars? Cars on hydrogen?
All good ideas and no. Customers!
sure, sadly neither me nor you are in charge of them 
As I said the community models are completely different, you cannot say one is better than the other, they are just different.
Everything in mainline branch (kopano)
Same release as prod but no advanced features (Zimbra).
Everyone for their own.
Zimbra you pay for the features you need.
Kopano you pay for the official releases.
I prefer Kopano you Zimbra that's great.
If you are a bank you want the minimum change possible to keep going. That's how they function. I work in that environment and trust me Ubuntu 16.10 will be here in 2028
If it is still missing then perhaps you should have asked them why and when it will be fixed.
I entirely disagree. Plenty of vendors still produced software for Windows XP although it was dead years ago.
The software you produce is for your customers, not for the beauty of it.
In Brasil cars run on ethanol, so you have to make engines for that.
Same.
I cannot comment whether the package exists or not as I did not have the chance to look at Centos (in fact I run Kopano on debian as you know).
All I said is that with a little bit of patience you would have had your answer and your system.
Anyway that's the end of the day so I am going home.
I run whatever makes sense in my environments. If I can I run Centos if I can't I run Ubuntu but only LTS because I can not be bothered to upgarde every 6 months (this has nothing to do with Kopano, I am talking about other software).
in terms of RPMs were missing I think you did have your answer in the forums and if the conversation did go down a different route (one way or another) I am sure you would have had your installation working in Centos.