Fix online "Subscribe Me" mailing list program on new server to send mail

We are in need of developer who can fix our "Subscribe Me" mailing list program on our new server. [login to view URL] When we login to this program and click on "Edit/Upgrade Configurations" and try and enter the correct new SMTP settings for the new server, it creates errors and does not update. We need a script expert who can get this program correct and working again. (The original creator of the program [Siteinteractive] is no longer in business). Let us know if you are able to deal with scripts of this nature and get this corrected. We just moved to a new server and the old server has already been decommissioned. However, we want to be able to get this working again correctly and sending mail.