Multipage Form and emailing

Hi there! Thank you very much for the plugin – I’ve just started to try and use it.

I’ve followed the steps regarding setting up a multistep form from here : https://xnau.com/creating-multiple-page-forms-in-participants-database/ but while I now have a multi step form, the confirmation email is not sending, though the confirmation page is displaying and records are being written to the db.

I’ve looked at https://xnau.com/work/wordpress-plugins/participants-database/participants-database-email-troubleshooting/ but I’m not seeing where I’m going wrong.

In the Apache logs I see errors like this:
...PDb_Signup::_mail sending failed for: [admin_contact_email_address], referer: ....

My initial page’s shortcode is like this:
[pdb_signup groups="main" action="signup-page-2" submit_button="Proceed To Application Form"]
All that page has is a big block of agreement text, a checkbox that’s to be required and the submit button.

signup-page-2 has the shortcode:
[pdb_record groups="personal" action="thank-you" submit_button="Complete the Signup"]

With the groups=”personal” containing the set of form fields I want a user to complete.
The thank-you page has the shortcode:
[pdb_signup_thanks]

For a multistep form, where you’d only have at most 2 pages of forms is the ‘pdb_record’ shortcode needed? My current guess is that the plugin just thinks that the form submission isn’t complete.

The ‘Send Signup Response Email’ option is set, as is ‘Signup Notification Recipients’ – which is set to [admin_contact_email_address] – the field listed in the signup-page-2 page.

I don’t suppose anyone can help? I’m using Version 1.6.2.5 of the plugin.

https://www.ads-software.com/plugins/participants-database/