How-to disable Joomla’s built-in contact forms component and its ability to send a copy to the sender, directly in your MySQL database using phpMyAdmin
Often the built-in Joomla contact forms component (com_contact) is abused by spammers. These contact forms allow the sender to receive a copy of the form contents. All spammers need to do is enter the email address of the target as sender/from. This way, anyone can use the Joomla contact form for spamming anyone. This short article explains how to disable and combat this.