Upgrading from old ZCS 4.5 on CentOS 5.x

[blueflametuna]

Greetings,
I am new to Zimbra. Have worked with Sendmail and Postfix previously.
Tasked with upgrading from ZCS Open Source 4.5.3? running on CentOS 5.x.
Sorry, details are sketchy. Recently invited to assist with this environment.

From what I have read so far, I will need to upgrade to ZCS 4.5.11 first, then up to 5.0.x (5.0.21 is the latest). Any recommendations for stability/features? Any reason to (or not to) go up to 6.0.4?

CentOS. Not supported. Works anyway?

Help with focus on search? I am sure this has been covered before.
Any assistance is appreciated.

[y@w]

Welcome to the forums

You're right on for the upgrade path.

CentOS is indeed not officially supported, though there are many who use it and it works just fine.

The only real reservation that I would have in going all the way to 6.0 is that it would be a lot to bite off in one upgrade, especially when you have to jump through 4.5.11 on the way.