If you're moving a site to Webvanta, you may need to move an existing email service as well. And if you're creating something new, you'll probably want to set up email as well as the web site.
In the past, web hosting companies typically provided email service, along with web hosting. But times have changed, and we've concluded that our clients are better off using existing email services. Quality email hosting today requires effective spam filtering, a good web interface, IMAP and POP3 support, and support for iPhones and other mobile clients. None of this has anything to do with providing a great content management system, which is where we focus our energy; other companies are focused on email and do a great job.
Google, in particular, provides a far better mail service than most web hosts can offer. You can use it for mail at your domain (it doesn't have to be @gmail.com), and you can use the web interface and/or enable IMAP or POP3 for use with a desktop mail client.
Unfortunately, Google has discontinued the free version of their email offering (unless you use gmail addresses). The cost is $50 per year per mailbox.
As an alternative, Rackspace provides quality email hosting for $2 per mailbox per month for the basic service.
When creating a Google Apps account, you can set it up to use any domain name that you control.
Note that we're not talking about setting up a gmail account. With Google Apps, you get the same user interface and features as Gmail, but it's using your own domain name.
Google's Setup Guide will guide you through the setup process.
If you haven't dealt with DNS settings (including CNAME and MX records) before, it might take a little study to become comfortable with it. But once you have this process down, you can set up mail for a new domain from start to finish in 15 minutes. The details of how you change the settings depend on your DNS provider, but what the settings do is always the same.
Note: Google is making lots of changes to their user interface for Google Apps, so the steps below may not apply exactly. The general approach remains the same, however.
When you change your domain's MX records, you're telling everyone sending email to your domain to deliver it to Google. There may be a delay of minutes to hours before the updated DNS propagates everywhere, however, so some email may be delivered to your old mail server for a day or so.
Once you log in to your google mail account via the web, you can enable POP3 and IMAP access. Then you can configure your email program (Outlook, Apple Mail, or anything else) to communicate with google's servers, and you're done.
Google's email settings are a little involved; there's lots of help here.