Recently (we think about 2 weeks ago), messages sent from our Wordpress website www.h2gold.com.au, using Contact Form 7 and Google recaptcha, stopped being received in our Zoho mail.

The website is about 4 years old, and was configured with Zoho's MX records from the start. And worked fine most of the time.

I have since updated Wordpress 5.3  and CF7 5.1.5 and also upgraded Captcha to V3 with new keys. All indications from the website indicate everything should be fine. Green box message "Thankyou your message has been sent" is displayed.  Yet the message is not received in the inbox or spam folder.

I have added the email address and domain to the Trusted addresses & domains lists.

Can anyone suggest why Zoho has stopped receiving our CF7 form emails??

Thanks in advance.