Email notification not sent

Hi Nikola,

Great app!

I hope you are able to help me out with my email configuration.
I have tried several settings and think I tried all that is suggested on the forum, but with none of the settings I tried the user receives a notification.
No notification when the appointment is made and no notification once I confirm (or cancel) via the reservation confirmation.

I have the following settings:
Email address for notifications: a gmail address (I receive all notifications)
Send email to worker: Not checked
Send email to customer: “Name <[email protected]>” – I have also tried “[email protected]”, “Name <[email protected]>” and “[email protected]: – none of these work

I have a custom field named “Email”
Email INPUT
Label :Email
Required : Yes
Visible : Yes

This is the latest error that I got:
———— ERROR #17 ————
TYPE: MAIL
ERRORS: {“wp_mail_failed”:[“You must provide at least one recipient email address.”]}
ERRORS_DATA: {“wp_mail_failed”:{“to”:[“”],”subject”:”Uw afspraak 8″,”message”:”<p>Geannuleerd\u00a0<\/p>\n<p>\u00a0<\/p>\n<p>In afwachting van bevestiging<\/p>\n<p>Geachte <span id=\”custom-tags\”>Merel Swarts<\/span><\/strong><\/p>\n<p>We hebben uw verzoek voor een afspraak op januari 14, 2017 om 10:00 am ontvangen. <br \/><br \/>Wij zullen u zo spoedig mogelijk een bevestiging van uw boeking doorsturen. <\/strong><\/p>\n<p>Met vriendelijke groet, <br \/>Neil Judkins<\/strong><\/p>\n<p>Fysio2Fit<\/strong><\/p>\n<p>\u00a0<\/p>”,”headers”:[],”attachments”:[],”phpmailer_exception_code”:2}}
———- ERROR #17 END ———-

Can you tell me where I am going wrong?
Many thanks,
Merel