AnkietyGO/profile-builder/front-end/default-fields/email/email.php

<?php
/* handle field output */
function wppb_email_handler( $output, $form_location, $field, $user_id, $field_check_errors, $request_data ){	
	$item_title = apply_filters( 'wppb_'.$form_location.'_email_item_title', wppb_icl_t( 'plugin profile-builder-pro', 'default_field_'.$field['id'].'_title_translation', $field['field-title'] ) );
	$item_description = wppb_icl_t( 'plugin profile-builder-pro', 'default_field_'.$field['id'].'_description_translation', $field['description'] );
	$input_value = '';
	if( $form_location == 'edit_profile' )
		$input_value = get_the_author_meta( 'user_email', $user_id );
	
	if ( trim( $input_value ) == '' )
		$input_value = $field['default-value'];
		
	$input_value = ( isset( $request_data['email'] ) ? trim( $request_data['email'] ) : $input_value );
	// filter must be applied on the $input_value so that the value returned to the form can be corrected too
	$input_value = apply_filters( 'wppb_before_processing_email_from_forms' , $input_value );

	if ( $form_location != 'back_end' ){
		$error_mark = ( ( $field['required'] == 'Yes' ) ? '<span class="wppb-required" title="'.wppb_required_field_error($field["field-title"]).'">*</span>' : '' );
					
		if ( array_key_exists( $field['id'], $field_check_errors ) )
			$error_mark = '<img src="'.WPPB_PLUGIN_URL.'assets/images/pencil_delete.png" title="'.wppb_required_field_error($field["field-title"]).'"/>';

		$extra_attr = apply_filters( 'wppb_extra_attribute', '', $field, $form_location );

        $output = '
			<label for="email">'.$item_title.$error_mark.'</label>
			<input class="text-input default_field_email" name="email" maxlength="'. apply_filters( 'wppb_maximum_character_length', 70 ) .'" type="email" id="email" value="'. esc_attr( $input_value ) .'" '. $extra_attr .' />';
        if( !empty( $item_description ) )
            $output .= '<span class="wppb-description-delimiter">'. $item_description .'</span>';

	}
		
	return apply_filters( 'wppb_'.$form_location.'_email', $output, $form_location, $field, $user_id, $field_check_errors, $request_data );
}
add_filter( 'wppb_output_form_field_default-e-mail', 'wppb_email_handler', 10, 6 );


/* handle field validation */
function wppb_check_email_value( $message, $field, $request_data, $form_location ){
	global $wpdb;
	// apply filter to allow stripping slashes if necessary
	$request_data['email'] = apply_filters( 'wppb_before_processing_email_from_forms', $request_data['email'] );
	if ( ( isset( $request_data['email'] ) && ( trim( $request_data['email'] ) == '' ) ) && ( $field['required'] == 'Yes' ) )
		return wppb_required_field_error($field["field-title"]);

    if ( isset( $request_data['email'] ) && !is_email( trim( $request_data['email'] ) ) ){
        return __( 'The email you entered is not a valid email address.', 'profile-builder' );
    }

	if ( empty( $request_data['email'] ) ) {
		return __( 'You must enter a valid email address.', 'profile-builder' );
	}

    $wppb_generalSettings = get_option( 'wppb_general_settings' );
	if ( isset( $wppb_generalSettings['emailConfirmation'] ) && ( $wppb_generalSettings['emailConfirmation'] == 'yes' ) ){
		$user_signup = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM ".$wpdb->base_prefix."signups WHERE user_email = %s AND active=0", $request_data['email'] ) );

        if ( !empty( $user_signup ) ){
            if ( $form_location == 'register' ){
                    return __( 'This email is already reserved to be used soon.', 'profile-builder' ) .'<br/>'. __( 'Please try a different one!', 'profile-builder' );
            }
            else if ( $form_location == 'edit_profile' ){
                $current_user = wp_get_current_user();

				if( ! current_user_can( 'edit_users' ) ) {
					if ( $current_user->user_email != $request_data['email'] )
						return __( 'This email is already reserved to be used soon.', 'profile-builder' ) .'<br/>'. __( 'Please try a different one!', 'profile-builder' );
				}
            }
        }
	}

	$users = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM {$wpdb->users} WHERE user_email = %s", $request_data['email'] ) );

	if ( !empty( $users ) ){
		if ( $form_location == 'register' )
			return __( 'This email is already in use.', 'profile-builder' ) .'<br/>'. __( 'Please try a different one!', 'profile-builder' );
		
		if ( $form_location == 'edit_profile' ){
            $url_parts = parse_url( $_SERVER['HTTP_REFERER'] );
            if( isset( $url_parts['query'] ) ) {
                parse_str( $url_parts['query'], $query );
            }

            if( isset( $_GET['edit_user'] ) && ! empty( $_GET['edit_user'] ) ) {
                $current_user_id = absint( $_GET['edit_user'] );
            } elseif( defined( 'DOING_AJAX' ) && DOING_AJAX && isset( $query['edit_user'] ) && ! empty( $query['edit_user'] ) ) {
                $current_user_id = $query['edit_user'];
            } else {
                $current_user = wp_get_current_user();
                $current_user_id = $current_user->ID;
            }
			foreach ( $users as $user )
				if ( $user->ID != $current_user_id )
					return __( 'This email is already in use.', 'profile-builder' ) .'<br/>'. __( 'Please try a different one!', 'profile-builder' );
		}
	}

    return $message;
}
add_filter( 'wppb_check_form_field_default-e-mail', 'wppb_check_email_value', 10, 4 );

/* handle field save */
function wppb_userdata_add_email( $userdata, $global_request ){
	// apply filter to allow stripping slashes if necessary
	if ( isset( $global_request['email'] ) ) {
        $global_request['email'] = apply_filters( 'wppb_before_processing_email_from_forms', $global_request['email'] );
        $userdata['user_email'] = sanitize_text_field( trim( $global_request['email'] ) );
    }

	return $userdata;
}
add_filter( 'wppb_build_userdata', 'wppb_userdata_add_email', 10, 2 );