The "User contact" block is the new release for moodle2 of the "Contact Form" block for moodle 1.x
Moodle is completely different and the name of this block too.

This block allows student to email the teacher of a course. If there are multiple teachers, the student gets to select the teacher(s) to send the email to. Copies are cc:d to the further hidden or visible recipients.

The version for Moodle 1.8 added the ability to include a hidden recipient.
The version for Moodle 1.9 added the ability to send return receipts, and moved the cc: and hidden recipients to roles.

The Contact Form block has been in existence since at least Moodle 1.5.
This block has had many contributers, from Daryl Hawes in Moodle 1.5, Daniele Cordella in Moodle 1.6, Matt Campbell in Moodle 1.7 & 1.8, Valery Fremaux in Moodle 1.8 and Daniele Cordella in Moodle 1.9 and 2.0

Because of this new release I ask for the access to contrib/plugins/blocks/user_contact