I'm having a few issues with some forms that were made for a client with version 8.3 build 206 some time back.
Apparently, when the form submit button is selected, it replies with a message that this email address doesn't exist and this error message is displayed:

Unable To Send E-Mail
We're sorry but we were unable to send your e-mail. If you are sure that you entered all your email addresses properly, you should contact your server administrator.

PHP Version: 5.2.17
Sendmail Path: /usr/sbin/sendmail -t -i
Sendmail From:
SMTP: localhost
SMTP Port: 25

MySQL: Installed

File Uploads: On
File Uploads Max Size: 40M
Post Max Size: 8M

Software Version: 8.0
Software Last Updated: 08/31/2007

Script Version: 5.0
Script Last Updated: 05/27/2009



The url of the form is https://skysat-europe.com/html/activation.html

It's probably a php version issue. Did your host recently upgrade it's version?
I would look at getting the new form builder.
http://www.coffeecup.com/web-form-builder/

I see you are still using the Classic version of Form Builder. This version has been discontinued for some time now in favor of the new HTML version of Web Form Builder that was released in October 2011. On May 1st, 2012 all support for the Flash version was discontinued and we are no longer offering the download of

Thanks Guys, looks like I am going to re-design all the forms with the latest Form builder.