gmail contact form not working

Hi,
I have been using contact form 7 for a while now on midstaffsmind.co.uk but it has suddenly stopped working. I checked the settings and there was no email address in the ‘to’ field (there must have been an update or something which removed this info?) so I typed in the relevant gmail address which we had successfully used with the form before and clicked save. Testing the form it still doesn’t send the email and comes up with a ‘failed to send’ red error box.

Any clues why this might be?

I haven’t added anything into any of the other fields, I have just typed the gmail address into the ‘to’ box in the ‘mail’ section of the settings. Presumably this is the correct way to setup the form? It worked perfectly on gmail previously.

Any help would be greatly appreciated, thanks.

https://www.ads-software.com/plugins/contact-form-7/