CPanel migration without Downtime

Been looking around for some solution for my problem.


the goal is to physically move Server 1 to another location.
For that i have a temp server on site.

Got 2 Servers (like everybody else)

Server 1 - colocation
Server 2 - On Site

So i was thinking moving all datat from server 1 to server 2. and when the physically move of server 1 i done, i would move back from server 2 to server 1.


Tried the "Copy multiple accounts/packages from another server"
but due to the excessive use of email, i've got 7GB+ to transer in 5 accounts, where 1 account is 5GB+ and another is 2GB+ , the 2 accounts with the most important mails..


1. I'm worried about loosing e-mails during the transfer.

2. tried to move it this night, no problems moving, but when i pointed the DNS to Server 2, the website wasn't working.


I do not have too deep linux experience.
some step-by-step would be great.

Any suggestions how to resolve this painless ?


/James

----- Edit
Allt the DNSing are on another server.