We are using ZCS 4.5.10 version on RHEL5 - 64 bit in production environment and one domain is working fine. SMTP relay has been configured on different server.
First time i am going to work on zimbra. I found that we are using very old version and latest version is zcs 5.
Can you please tell me what are the additional features it has than the old one ?
I searched on net and found that to upgrade this version, I have to only select upgrade ..that's it and it will automatically upgrade .
Is this that easy ? How much downtime it will required ? Is there any possibility to loose data, contacts ? what steps client need to do at there end after upgrade?