http://www.jivesoftware.org/builds/wildfire/docs/3.1.0_beta_2/documentation/ldap-guide.html
contains:
<EMAIL>
<INTERNET/>
<USERID attrs="mail">{0}</USERID>
</EMAIL>
and seems not to work as expected while
<EMAIL><HOME/><INTERNET/><PREF/><USERID attrs="mail">{0}</USERID></EMAIL>
does work