What is the crowd's opinion of Zimbra Collaboration Suite?

From 3.5 billion comments

I've heard about, but have not use it:

https://www.zimbra.com/email-server-software/product-edition-comparison/

However you should really think about moving on-premise/self-hosted. Just looking at the mail storage requirements in my own environment is enough to scare me away from it.

I prefer G Suite to handle the nightmare for me...

Community Edition for Open Source no longer supports MS ActiveDirectory or other external LDAP. You have to use the built-in Zimbra LDAP. That or get paid Network Edition and authenticate in a variety of ways.

Product comparison document found here: https://www.zimbra.com/email-server-software/product-edition-comparison/

You have to pay for Zimbra to get the actual Exchange functionality, though.

https://www.zimbra.com/email-server-software/product-edition-comparison/

But otherwise yes, Zimbra is a feature-rich suite that makes setting up a mail server very easy!