Getting rawlogging working with dovecot 2.2

According to this manual[1] I just have to add these lines to my config, not?

protocol imap { rawlog_dir = /tmp/rawlog/%u }

I should be seeing something in this /tmp/rawlog if I delete an message via imap not? I have already made this folder 777 and /tmp/rawlog/test 777, but still nothing is there. The normal syslog of dovecot does not report any errors.

[1] https://wiki2.dovecot.org/Debugging/Rawlog