Why is the validation not triggering at all?

If you submit the form with mismatched emails and it still goes through, double-check your form tag names. The PHP code explicitly targets client-email-confirm. If your tag in the CF7 editor is named email-2 or anything else, the if statement in the PHP function will evaluate to false, and the code will be bypassed entirely. Ensure the tag names in Step 2 exactly match the variables in Step 3.

Can I use this for multiple forms on the same site?

Yes. The beauty of this specific cf7 confirm email validation script is its reusability. As long as you use the exact field names (client-email and client-email-confirm) in any other Contact Form 7 form on your site, this single snippet in your functions.php will automatically protect those forms as well. It globally hooks into the validation process.

The error message shows, but the email still sends?

This is extremely rare and usually indicates a severe conflict with another plugin that is aggressively overriding the wpcf7_before_send_mail action. It can also happen if you are running an outdated version of PHP (below 7.4) that fails to process the object methods correctly. Ensure you are running PHP 8.0+ and temporarily disable other SMTP or form-enhancement plugins to isolate the conflict.

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