Make sure you have Java 6 installed and set as current version by checking
JAVA_HOME:
Unix/OSX:
echo $JAVA_HOME
Windows:
echo %JAVA_HOME%
Check if you already have Apache Ant installed : ant -version
If you don't, download and unzip ant from ant.apache.org,
add ant/bin full path to the PATH environment variable.
Get DavMail source package from sourceforge and uncompress it:
tar xvzf davmail-src-*.tgz
or checkout trunk:
svn co http://davmail.svn.sourceforge.net/svnroot/davmail/trunk
or get and uncompress tarball from
http://davmail.svn.sourceforge.net/viewvc/davmail/trunk