found this: http://library.linode.com/web-server...dosemailnotify
NOTE: Be sure MAILER is set correctly in mod_evasive.c
(or mod_evasive20.c). The default is "/bin/mail -t %s" where %s is used to denote the destination email address set in the configuration. If you are running on linux or some other operating system with a different type of mailer, you'll need to change this.
is that needed if I installed libapache2-mod-evasive via apt-get? shouldn't is my guess...