Email Server High Availability

Hello,

We are planning to setup a Email server with High Availability for email services so that if SMTP/POP/IMAP goes down on one server, the services switch to second server.
We are planning to use a Linux machines from a hosting provider and will do it using DNS with multiple MX records with round robin.

Now i have couple of queries regarding this setup :-

  • Is this possible to have a same domain name to bind with 2 IPs i.e xyz.com point to 1.1.1.1 on one server and xyz.com point to 2.2.2.2 on second server.
  • How can we setup MX records for each server on DNS for email failover.
  • As we have a separate servers for this setup that means data related to email would be reside on separate server (because they have separate HDD), so in case 1st server goes down and it switch to second server, will i skipped my email which was received on 1st server before it goes down as my email client will receive them on certain period of time.

Please let me know if above is a valid query.