Can I do backup of my mails myself?

Backup of your mailbox can be done using any IMAP client.
One such freeware client for Windows is IMAPSize. It can be downloaded from http://www.broobles.com/imapsize/index.php

The parameters are the same as for your account defined in the control-panel.

Mac and other Unix users can use the imapbackup utility that can be downloaded from  http://the.taoofmac.com/space/projects/imapbackup

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