Can I use multiple email servers at once?

I was wondering: Can you use multiple email servers at once? In this case, I was going to add all the Google Apps MX records then add the MX records of another email server.

My goal here is to only use the somewhat expensive Google Apps for only important email addresses (eg all the employees), then use the other cheap email server for other email addresses like webmaster and some other unimportant but needed emails.

My thought is that a mail message would try the first 5 Google Apps mail servers, fail, then go to mine and succeed.

Would this work? If not, are there any other options?

Solution 1:

There are some options for split delivery in Google apps. This feature seems to be aimed at easing the tradition from your old mail system to Google apps, specifically so you can slowly transition people over a little at a time. But I don't see any reason why you couldn't set this up, and run with it.

I haven't set this up, but from what I understand from reading the docs, you set your MX at Google. Google will accept messages for accounts that live on the Google domain, and will forward everything else off to a server you configure.

For this to work you are almost certainly going to need to perform some configuration of your other mail server as well to perform the same step. If the account isn't local, but the destination is for your domain, then forward to Google.

Solution 2:

Not the way you'd hope. All mailers are not created equal, some some stupid mailers will try-once-then-DSR. Or try-once-then-requeue. The email addresses on the servers with lower MX priority will absolutely miss emails. Nor is there any guarantee that mailers will even respect the MX priority settings, so you'd get attempts to your 'cheap-seats' servers, and as these mailers tend to be broken in other ways they're less likely to fail 'up' to your 'executive seats' addresses.

The more correct way of doing this is to set up a pair of Smart Hosts that'll do the forwarding you're looking for. The serious down-side to this is that you'll lose what is perhaps the best but hidden feature of GoogleApps, anti-spam; you'll have to do AS yourself. If you find yourself thinking about spending money on it, the GoogleApps fee may seem cheap by comparison.