Steps to proceed

In order to require users to confirm their registration and to provide a valid email address, click the  button to open the drawer menu, then click on "Administer Wiki":

In the wiki preferences page, click on the "Registration" link from the vertical menu to the left:

Next, set "Use email verification" to "YES" which means that an email will be sent to the email address the user registered with. The content of the message is set in the "Validation E-Mail Content" text area.

Registration Options

• Registration page heading is the line displayed at the top of the page for the users who are registering or who have just registered.

• Confirmation E-Mail Content requires that you set "Use email verification". These settings are optional but you will still have to provide a link to activate the account.

  

• Welcome Message requires that you set "User email verification" to "YES" and modify the "Validation E-Mail Content" so that it doesn't mention the verification since it is not needed anymore.

  

• Enable login button - enables or disables the button the users need to click on in order to log in.

• Enable automatic login - disabled by default. If enabled, the user is automatically logged in after a successful registration.

• Redirect here after registration - refers to the URL of the wiki page the user will be redirected to after clicking the "Login" button, default value - URL of XWiki Home page

  /xwiki/bin/view/Main/

• Require captcha to register - requires the user to solve a CAPTCHA in order to register.

• Registration Successful Message - is displayed when the user has successfully registered.

• Require a password with the given length - user must specify a password no shorter than the number of characters

• Require at least one lower case character in the password - user must use at least one lowercase character

• Require at least one upper case character in the password - user must use at least one uppercase character

• Require at least one number in the password - user must use at least one number character

• Require at least one symbol character in the password - user must use at least one special symbol character

Result

This is how it looks the registration form after the configuration: