From Online Manual
Why is "wwwRedirect" in my forum URL?
When you set up your forum, you specified that the site URL was www.yoursite.com, but when you try to access it, you are using the domain "yoursite.com". As a result, SMF redirects you to the www URL of your site address.
If you wish to change this behaviour, there are three options:
- Access the site using the www.
- Change your site settings to remove the www from your site URL and all the URLs of themes, smilies, and attachments (use repair_settings.php to do this).
- Use a .htaccess redirect to automatically (and invisibly) redirect users to the version of your URL that you want to use.