Microsoft Live Custom Domains are now shutting down. I have been using this service for e-mail hosting for all my Microsoft Azure Websites, but now it is gone and no viable repl
How many real people do you have reading e-mail? As many as you got mailboxes? If not, then I really suggest you go for Exchange Online from Microsoft which goes for $4 per user (not mailbox) per month.
The trick is, that once you've set up your domains, you create a Shared Mailbox through PowerShell and while doing so, you give the real people (you pay for) the rights to read and send as. The cool thing is, that the user does not need to do anything. The mailbox simply appears in their Outlook.