Error on user creation - Send Mail

Hello - I am receiving this everytime I add an user
exception 'Zend_Mail_Transport_Exception' with message 'Unable to send mail. ' in /var/www/application/libraries/Zend/Mail/Transport/Sendmail.php:112

Stack trace:

#0 /var/www/application/libraries/Zend/Mail/Transport/Abstract.php(348): Zend_Mail_Transport_Sendmail->_sendMail()

#1 /var/www/application/libraries/Zend/Mail.php(973): Zend_Mail_Transport_Abstract->send(Object(Zend_Mail))

#2 /var/www/application/controllers/UsersController.php(270): Zend_Mail->send()

#3 /var/www/application/controllers/UsersController.php(201): UsersController->sendActivationEmail(Object(User))

#4 /var/www/application/libraries/Zend/Controller/Action.php(513): UsersController->addAction()

#5 /var/www/application/libraries/Zend/Controller/Dispatcher/Standard.php(289): Zend_Controller_Action->dispatch('addAction')

#6 /var/www/application/libraries/Zend/Controller/Front.php(946): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))

#7 /var/www/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(77): Zend_Controller_Front->dispatch()

#8 /var/www/application/libraries/Zend/Application.php(358): Zend_Application_Bootstrap_Bootstrap->run()

#9 /var/www/admin/index.php(31): Zend_Application->run()

#10 {main}

Should I have installed sendmail in addition to LAMP and SSH for Ubuntu 10? Thanks

For Omeka's normal mail delivery operations to work, you need some sort of MTA installed on your system, be it sendmail or some other sendmail-compatible alternative.

Ran:

sudo apt-get install sendmail

and no more complaints on user creation