I currently have the company's email hosted by the ISP. Long story short I want to move to a different email provider (possibly self-hosted Zimbra). As I am not familiar with installing and managing a mail server is it possible for me to install Zimbra on the company's local server (VMware vSphere) and set it up, so that incoming email will arrive at both the current mail server at the ISP and also on the local Zimbra server?
I will not change my users to send or receive through Zimbra. They will continue to use the ISP's mail server for the time being. I just want to get familiar with Zimbra and also I want to verify whether the same amount of incoming emails are received on both mail servers! The reason for this is that many emails from our clients are disappearing not reaching us and the problem lies somewhere at the ISP.
Just a thought, but if I setup Zimbra and then create a second mx record on the ISP's DNS pointing to Zimbra will incoming mail arrive at both servers?