What part of my SMTP is wrong to cause this change?

There was an error on your SMTP configuration. Due to that error, our system automatically changed your email sender's address for your form ID 42726446953160 to noreply@jotform.com to prevent issues arising from your account.

It looks like that you have configured SMTP email address using Mandrill. As per the recent announcement from Mandrill, it is required to have a paid monthly MailChimp account and verify domain ownership in order to send emails using Mandrill. The due date was 27th April 2016 to merge Mandrill account with MailChimp account. Here is the blog post from Mandrill that can provide you with more information in this regard. 

http://blog.mandrill.com/important-changes-to-mandrill.html

This may have your Mandrill account disabled and hence the account sender email address is switched to JotForm default email address. At the moment, if you want to send emails using your email address you may configure SMTP using your direct email settings. Please see the guide below:

http://www.jotform.com/help/244-How-to-Setup-SMTP-for-a-Form

Hope this information helps!