Transfer mail til new server, maybe MEroute?

[Thomas Pedersen]

Hi,

I need to move mail from a MailEnable 4.26 to 8.55 both on Plesk servers.
Plesk can transfer all the data but this is very slow, and by the time the last one has finished new mails have arrived.
Plesk is unable to transfer changes, so I tried to just copy mails from the old postoffice to the new one, but the mails are not showing up in webmail.
Then I thought maybe MEroute could do the trick. I'm thinking something like this...

1) Set up MEroute on all domains and point to a unused IP.
2) Transfer mail to new server, while mails presumably just pile up in queue.
3) When transfer is finished, change new server IP to the unused IP from step 1 and boom, mail starts to deliver to new server.
4) I change IP on new server to the old IP and suffer only 10 seconds "downtime".

I have a few doubts and worries about my brillant plan.

1) Will mail be queued and for how long?
2) Is there a way to set MEroute for all domains bulk like, or do I have to do it manually one by one (please let it not be so).