Question Backup to another server

[DamianM]

Hi all,
my company use Plesk panel on dedicated server. This configuration was made by another worker.
Now we would like to have backup server to run if first server is down.
I install plesk on second server and rsync backup files.
I restore full backup on second server. I see email accounts but I can't open webmail website.
First server is mx10 and second is mx20. It is added to DNS. MX20.domain is working but webmail.mx20.domain is not.
Can you help me? I am new in plesk and mail servers.
My plan is:
1. Backup first server.
2. Do a second server with plesk.
3. Restore backup from first server on second server.
4. Have 2 separately servers: MX10 and MX20.
5. Rsync folders with e-mails and emails filters from first to second server (can somebody write which folders?).
6. Use floating IP to manually connect e-mail from first to second server.
Any sugestion?