backing up IMAP server on a hard drive

Hi, I am trying to back up my IMAP server to a hard drive. Later I intend to extract all mails for attachments. What do you reckon is the best too to perform this ?

Imapsync or Thunderbird (or something else, please recommend)

One problem I am having with imapsync is the setting for host2 (being a localhost computer). How does one set a parameter for host2 being a desktop computer.

Thanks Kevin