function bbp_user_email_change_handler( $action = '' ) {

	// Bail if action is not `bbp-update-user-email`
	if ( 'bbp-update-user-email' !== $action ) {
		return;
	}

	// Bail if not on users own profile
	if ( ! bbp_is_user_home_edit() ) {
		return;
	}

	// Bail if not attempting to modify user email address
	if ( empty( $_GET['newuseremail'] ) && empty( $_GET['dismiss'] ) ) {
		return;
	}

	// Get the displayed user ID & option key
	$user_id     = bbp_get_displayed_user_id();
	$key         = '_new_email';
	$redirect_to = bbp_get_user_profile_edit_url( $user_id );

	// Execute confirmed email change.
	if ( ! empty( $_GET['newuseremail'] ) ) {

		// Check for email address change option
		$new_email = get_user_meta( $user_id, $key, true );

		// Redirect if *no* email address change exists
		if ( false === $new_email ) {
			bbp_redirect( $redirect_to );
		}

		// Cleanup & redirect if *invalid* email address change exists
		if ( empty( $new_email['hash'] ) || empty( $new_email['newemail'] ) ) {
			delete_user_meta( $user_id, $key );

			bbp_redirect( $redirect_to );
		}

		// Compare hashes, and update user if hashes match
		if ( hash_equals( $new_email['hash'], $_GET['newuseremail'] ) ) {

			// Does another user have this email address already?
			if ( email_exists( $new_email['newemail'] ) ) {
				delete_user_meta( $user_id, $key );

				bbp_add_error( 'bbp_user_email_taken', __( '<strong>ERROR</strong>: That email address is already in use.', 'bbpress' ), array( 'form-field' => 'email' ) );

			// Email address is good to change to
			} else {

				// Create a stdClass (for easy call to wp_update_user())
				$user             = new stdClass();
				$user->ID         = $user_id;
				$user->user_email = esc_html( trim( $new_email['newemail'] ) );

				// Attempt to update user email
				$update_user = wp_update_user( $user );

				// Error(s) editing the user, so copy them into the global
				if ( is_wp_error( $update_user ) ) {
					bbpress()->errors = $update_user;

				// All done, so redirect and show the updated message
				} else {

					// Update signups table, if signups table & entry exists
					// For Multisite & BuddyPress compatibility
					$bbp_db = bbp_db();
					if ( ! empty( $bbp_db->signups ) && $bbp_db->get_var( $bbp_db->prepare( "SELECT user_login FROM {$bbp_db->signups} WHERE user_login = %s", bbp_get_displayed_user_field( 'user_login', 'raw' ) ) ) ) {
						$bbp_db->query( $bbp_db->prepare( "UPDATE {$bbp_db->signups} SET user_email = %s WHERE user_login = %s", $user->user_email, bbp_get_displayed_user_field( 'user_login', 'raw' ) ) );
					}

					delete_user_meta( $user_id, $key );

					bbp_redirect( add_query_arg( array( 'updated' => 'true' ), $redirect_to ) );
				}
			}
		}

	// Delete new email address from user options
	} elseif ( ! empty( $_GET['dismiss'] ) && ( "{$user_id}{$key}" === $_GET['dismiss'] ) ) {
		if ( ! bbp_verify_nonce_request( "dismiss-{$user_id}{$key}" ) ) {
			bbp_add_error( 'bbp_dismiss_new_email_nonce', __( '<strong>ERROR</strong>: Are you sure you wanted to do that?', 'bbpress' ) );
			return;
		}

		delete_user_meta( $user_id, $key );
		bbp_redirect( $redirect_to );
	}
}