Good afternoon, I am moving my accounts to a new server and one of my domains I can not afford for the email to be down while the nameservers are propogating. How can I set the system up so I do not see any downtime where the emails won't bounce? Do I need to set up some kind of MX record or something? I would appreciate any help you could provide to me.

I would go to the old DNS first, change the MX record to the new IP address. Depending on your TTL, this should not take too long to take affect.

After this, your email will be directed over to the new mail server. And now, you can update your DNS / change your name servers. Your mail server should be pointing to the new IP on the new DNS so you should not have any downtime / problems