How to upgrade mail server with minimum downtime.

[PaddingtonC]

I have an Expand server which connects to 4 Plesk webservers servers and a Plesk 9.5.4 Mail server. The mail server hosts email accounts for the 4 mentioned webservers which amounts to 12000 email accounts. I need to upgrade the server from the legacy hardware it is on.

I need help with:

1) How do I migrate data from the old server to the new one with minimum down time?
2)How do I copy data across to the new server without losing emails?
3) Is it a good practise too install the new server's hard drive into the current (old) mail server and rsyncing the data then installing the hard drive back into the new server. I am thinking of doing this as a data migration tool?
4)Does the Plesk Migration manager help with Email migration as well?

Any advice is welcome.

 

[abdi]

Since you seem to have physical access to the hardware it self, I would suggest you try option #3 first

3) Is it a good practise too install the new server's hard drive into the current (old) mail server and rsyncing the data then installing the hard drive back into the new server. I am thinking of doing this as a data migration tool?