I already have a system in place which includes a web server for hosting my family website, mail server (running postfix), and also have https for my webmail (currently using openwebmail)

My question is, how would installing zimbra affect everything that is alreay running on this server? I don't have the option of standing up a new system so everything would have to be on this one system.

Thanks, and I hope that I am able to use this great looking program without too much hassle.