I am in the process of migrating from an off site ISP provided pop/imap server to an in-house Zimbra setup and would appreciate any advice or experience in setting this up. I am installing Zimbra on an FC4 box on my network. Right now, almost all of my 300+ users are using POP3 with MS Outlook as a client. Most of them have saved their passwords so they don't remember it. Issues I am looking for advice on are:
1. Importing all the users into Zimbra so that they have to reset their passwords on first login in the web interface (since they dont know their passwords, I was going to set them to all be the same that way I dont have to individualize setup instructions)
2. Whether or not to pull the switch on all accounts at the same time or to setup a split domain as per the wiki. (leaning towards all at once for ease and because not a ton of users)
3. DNS issues. I am planning on having my ISP change my MX record to point to my IP instead of the old one, but leave the old one as a backup MX. Is this a good idea?
Thanks for any advice.