[VM] Specifying coding system for Imap.cache files

[blueman]

When running vm on a Windows machine, I typically add
( "^C:/myhome/mail/" 'raw-text-unix) to the alist file-coding-system-alist 
since I want to keep all my mail files in the unix file system coding without 
the annoying carriage returns (^M) at the end of each line.

However, this doesn't seem to be working for the imap-cache folders even though 
they are stored in the same mail heirarchy...

Unfortunately, these ^M characters then seem to sometimes generate an error 
when reading imap mail since the coding system gets messed up.

So, is there any way to get the imap-cache files to respect the file
coding system that I am setting for their directory? i.e., is there a way to 
specify the coding system that vm uses to write to an imap-cache file?

Thanks