Desknow vesion I used allows only POP3 access.
Looking at how Desknow is storing the data, it has the following directory structure:
desknowdata\
usermail\
<domain>\
<user>\
Inbox\
11a8ccfd307_N93M_34-0.eml
11a8ccfd307_N93M_50-0.eml
11a9e179bdc_49LX_8-0.eml
*.eml
Drafts\
Sent\
Deleted\
Folders\
FromFriends\
FromColleagues\
At the lowest are those .eml files.