Move mailbox contents from one server to another in Linux

Greetings! Im currently using Plesk and I need to move two mailboxes from one server to another, but here is the problem: One of the server's OS crash, but the data is still intact I was able to mont the HDD as as salve but is only as Read-Only... right now, a new OS has been installed in a new HDD and I need to move the qmail information from one HDD to the other. I just need two mailboxes, the rest can be deleted. Can it be done? I try doing this: [login to view URL] But didnt worked for me, or may be I didnt did it correctly And can someone help me with this?