Joomla! has the ability to manage contacts for your visitors. Joomla! gives you multiple ways to engage your site visitors with this. Some areas that might be of value to you are say, setting up separate contacts for support or sales.
In most sites, there is the ability for your visitors to reach you via your site. This is typically a section called CONTACT US. Joomla! has the native ability to make this easy to do through the use of a CONTACT FORM. The SITE contact is the means to do that.
The beauty of this is that it hides your email address from the public, thus lowering the chances a spam bot will grab it and add you to its list.
If you have to change a contact name, you can simply change the name and contact information ...