Simplest one-line method for getting and storing mail each minute as user zarafa over a secure connection would probably be (example working for Debian):

* * * * * zarafa /usr/bin/getmail_fetch --quiet --delete --ssl --timeout=30 mail.domain.com <REMOTE_MAILBOX> <REMOTE_PASSWORD> '| /usr/bin/zarafa-dagent -s <LOCAL_MAILBOX>'

PS: Note the shell escapes, they are required for the pipe.