Recovering Mail

[David Frey]

I have a backup of /var/spool/cyrus/mail from when I was running 
cyrus-imapd 1.5.19-15 in Debian.  I upgraded to 2.1.15-10, but had to 
downgrade after I realized that the mail storage format had changed.  I 
forgot to recover my user.dfrey.Sent folder before going back up to 
2.1.15.  Is there a way I can use my backup to recover my sent folder 
without downgrading again?

Thanks,
David Frey