diff --git a/includes/class-wc-checkout.php b/includes/class-wc-checkout.php
index 64236abd826..edab882884d 100644
--- a/includes/class-wc-checkout.php
+++ b/includes/class-wc-checkout.php
@@ -697,9 +697,10 @@ class WC_Checkout {
 				}
 
 				if ( in_array( 'email', $format, true ) && '' !== $data[ $key ] ) {
+					$email_is_valid = is_email( $data[ $key ] );
 					$data[ $key ] = sanitize_email( $data[ $key ] );
 
-					if ( $validate_fieldset && ! is_email( $data[ $key ] ) ) {
+					if ( $validate_fieldset && ! $email_is_valid ) {
 						/* translators: %s: email address */
 						$errors->add( 'validation', sprintf( __( '%s is not a valid email address.', 'woocommerce' ), '<strong>' . esc_html( $field_label ) . '</strong>' ) );
 						continue;