QContacts can be configured to provide two different kind of feedback to confirm that a form has been successfully submitted.

A parameter After Form Submission is available in global and contact configuration.

Options should be self-explanatory:

Reload form page with message. This is how the standard contact component works: after form submission the form page is displayed again with a 'Thank you' message at the top.

Please see this faq if the message is not displayed.

Confirmation in a separate page. After form submission users are directed to a separate page.

Title and text of the confirmation page are in language file to allow translations.

Example: [Joomla! frontend]/language/en-GB/en-GB.com_qcontacts.ini

CONFIRMATION_TITLE=Thank you!
CONFIRMATION_MESSAGE=Your message has been sent. Thanks for contacting us.
GO BACK=Go Back

Customize the text to the right of the equal sign as you like. For language files different than English / Italian the lines above may be missing if the translation has been made for an old version of QContacts. If that's the case simply add these lines at the end of the language file: remember that the key (the part to the left of the equal sign) must be uppercase and the language must be saved with utf-8 encoding.

If customizing the text is not enough you can edit the template in

[Joomla! frontend]/components/com_qcontacts/views/contact/tmpl/default_confirm.php