Migration from CSCMail 1.6.1 to Pronto! is easy especially if you use Pg or MySQL for a db backend.

• mv ~/.cscmail ~/.pronto
• mv ~/.cscmailrc ~/.prontorc
• edit ~/.prontorc with your favorite editor and replace all instances of cscmail with pronto
• tar xvzf pronto-1.0.0.tar.gz
• cd pronto
• make install or make install PREFIX=/usr for /usr
• cd /usr/lib/pronto
• ./migration-scripts/AddBccSearch
• ./migration-scripts/AddBodyText
• (if you were using 1.6) ./migration-scripts/mkmimetable.pl

Unfortuntaely, CSV does not support alter table statement and since its needed for upgrading to the newer version, CSV users may choose to edit ~/.pronto/messages and add the needed fields manually ( not recommended )
here is what I recommend:

• Right click on your folder list and click export folder for each folder you have.
• tar xvzf pronto-1.0.0.tar.gz
• cd pronto
• make install or make install PREFIX=/usr for /usr
• startup Pronto!
• set your accounts and filters.
• right click on your folders and import back into Pronto the folders you had previously exported.
• consider a real db backend :)