I moved my email server from Microsoft Exchange Server to Google Apps about two weeks ago.
- I no longer have to worry about backing up my email server.
- I can access my email through a browser without any special setup, firewall configuration or security worries.
- I don't need to run an Exchange Server which was killing my server, adding a second server for a small company seemed a bit overkill.
- I can get an IMAP server (or POP3) so can still use Outlook if I want to.
- It's free! I have a Windows 2003 Small Business Server so that's not a big problem for me but it's definitely worth considering if you don't have the licenses.
- Search is quicker, through the web interface.
- I no longer have full control over my email, if Google pack up shop, how do I get it all back?
- I have to trust Google to not read any sensitive information.
- I don't have as much potential storage, although 4GB of mail is a lot of mail!
- If I want shared calendars I have to use the web interface, which I don't like as much as Outlook.
All in all I'm pretty happy with the change. It's made my server a lot quicker now I can stop exchange server and speed up my acceptance/test sites, and my backups are smaller. The only thing that is really annoying is that some of my old email is trapped in exchange, I've got a local copy in Outlook but that's not an ideal solution. If you're shopping for a mail server I'd definitely consider it before rushing out and buying Exchange if you've only got a few users. There is a version of Google Apps which you can pay for but I haven't taken that version for a spin.