In some of our servers, we have disabled PHP mail function due to security reasons. WordPress/Joomla are kind of software which has lot of security issues as far as the way most of clients use it. ( due to out dated installations, Unsecured 3rd party plugins, more vulnerable templates)

Since PHP mail() function has disabled on some servers, you might not be able to send and receive emails directly through WordPress or Joomla. In that case, please following below steps

1. Create email account from your cpanel to use as outgoing email id. Example, if your domain is xyz.com, you can create email like info@xyz.com

2. Specify credentials of created email account under outgoing email configuration of your CMS.

In WordPress, you can use one of below plugins,

http://wordpress.org/extend/plugins/wp-mail-smtp/

In Joomla, SMTP authentication supported by default. http://help.joomla.org/content/view/51/153/1/7/