download the packages from Zimbras website for your distribution.
Read the install documentation,
prepare your system with the packages you need per the instructions
Install the zimbra packages you downloaded onto your Linux box..
Should take no more than 15 - 30 minutes to setup and configure Zimbra to a running state from start to finish.
Zimbra is really simple to get running.
A bit overkill if the server is for only one person though.