I'm currently migrating a website to another server, and want to test the DNS configuration (more specifically, email mx records) before moving the domain over. I've configured the DNS on the new server to have mx entries for Google Apps in the same way that it's configured on the old server. The domain is controlled by nameservers on the old server at the moment, so the change would simply be updating the nameservers to the new servers. (What I'm getting at is DNS is controlled at the server level, not registrar level).
Since the website has quite a number of users, I want to make sure the configuration is right before flicking the switch. For this, can I add an entry to the hosts file of my local computer to point the domain to the new server? I've done this, and the web server works, but would this also test the email mx records on the new server?