diff --git a/include/class-Mailforwardfrom.php b/include/class-Mailforwardfrom.php
index eaa1971..4a5d4d8 100644
--- a/include/class-Mailforwardfrom.php
+++ b/include/class-Mailforwardfrom.php
@@ -1,94 +1,117 @@
 <?php
-# Copyright (C) 2018, 2019 Valerio Bozzolan
+# Copyright (C) 2018, 2019, 2020 Valerio Bozzolan
 # Boz Libre Hosting Panel
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as
 # published by the Free Software Foundation, either version 3 of the
 # License, or (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
+/**
+ * Methods for a Mailforwardfrom class
+ */
 trait MailforwardfromTrait {
 	/**
 	 * Get the mailforward from ID
 	 *
 	 * @return int
 	 */
 	public function getMailforwardfromID() {
 		return $this->get( 'mailforwardfrom_ID' );
 	}
 
 	/**
 	 * Get the mailforward from address
 	 *
 	 * @return string E-mail
 	 */
 	public function getMailforwardfromAddress() {
 		return sprintf( '%s@%s',
 			$this->getMailforwardfromUsername(),
 			$this->getDomainName()
 		);
 	}
 
 	/**
 	 * Get the mailforward from username
 	 *
 	 * @return string
 	 */
 	public function getMailforwardfromUsername() {
 		return $this->get( 'mailforwardfrom_username' );
 	}
 
 	/**
 	 * Get the mailforward permalink
 	 *
 	 * @param $absolute boolean
 	 * @return string
 	 */
 	public function getMailforwardfromPermalink( $absolute = false ) {
 		return Mailforwardfrom::permalink(
 			$this->getDomainName(),
 			$this->getMailforwardfromUsername(),
 			$absolute
 		);
 	}
+
+	/**
+	 * Normalize a Mailforwardfrom object after being retrieved from database
+	 */
+	protected function normalizeMailforwardfrom() {
+		$this->integers( 'mailforwardfrom_ID' );
+	}
 }
 
 /**
  * An e-mail forwarding
  */
-class Mailforwardfrom extends Domain {
+class Mailforwardfrom extends Queried {
+
 	use MailforwardfromTrait;
+	use DomainTrait;
 
+	/**
+	 * Constructor
+	 */
+	public function __constructor() {
+		$this->normalizeMailforwardfrom();
+		$this->normalizeDomain();
+	}
+
+	/**
+	 * Database table name
+	 */
 	const T = 'mailforwardfrom';
 
 	/**
 	 * Update the related database row
 	 */
 	public function update( $columns ) {
 		query_update( self::T, $columns, sprintf(
 			"mailforwardfrom_ID = %d",
 			$this->getMailforwardfromID()
 		) );
 	}
 
 	/**
 	 * Get the mailforward permalink
 	 *
 	 * @return string
 	 */
 	public static function permalink( $domain, $mailforward = false, $absolute = false ) {
 		$part = site_page( 'mailforward.php', $absolute ) . _ . $domain;
 		if( $mailforward ) {
 			$part .= _ . $mailforward;
 		}
 		return $part;
 	}
 }