diff --git a/.gitignore b/.gitignore
index b74decb..57b2751 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
 /config.php
+/config-*
+
diff --git a/bot.php b/bot.php
index abba031..81161c0 100755
--- a/bot.php
+++ b/bot.php
@@ -1,245 +1,288 @@
 #!/usr/bin/php
 <?php
 
 // use system signals
 pcntl_async_signals( true );
 
 // install new signal handlers
 pcntl_signal( SIGTERM, 'sig_handler' );
 pcntl_signal( SIGINT,  'sig_handler' );
 
 // register some inline options
 $opts = getopt( '', [
 	'config:',
 ] );
 
 // config file
 $CONFIG_FILE = isset( $opts['config'] ) ? $opts['config'] : 'config.php';
 
 // import configuration
 require $CONFIG_FILE;
 
 /**
  * Blacklisted addresses
  *
  * See https://gitpull.it/T316
  */
-$sender_blacklist = $IMAPBOT->SENDER_BLACKLIST ?? [];
+$blacklist_sender   = $IMAPBOT->SENDER_BLACKLIST   ?? [];
+$blacklist_receiver = $IMAPBOT->RECEIVER_BLACKLIST ?? [];
+
+// check if we are in debug headers mode
+$DEBUG_HEADERS = defined( 'IMAPBOT_DEBUG_HEADERS' ) ? IMAPBOT_DEBUG_HEADERS : false;
 
 // load the IMAPSpooler class
 require IMAPBOT_PATH_SPOOLER;
 
 // declare used classes
 use reyboz\IMAPSpooler;
 
 // imap connection
 $spooler = new IMAPSpooler(
 	IMAPBOT_IMAP_MAILBOX,
 	IMAPBOT_IMAP_USERNAME,
 	IMAPBOT_IMAP_PASSWORD
 );
 
 // import phabricator stuff
 $phab_root = IMAPBOT_PATH_PHAB;
 require_once $phab_root.'/scripts/__init_script__.php';
 require_once $phab_root.'/externals/mimemailparser/MimeMailParser.class.php';
 
 // set the callback for every e-mail
-$spooler->setEmailHandler( function ( $body, $headers, $info ) use ( $sender_blacklist ) {
+$spooler->setEmailHandler( function ( $body, $headers, $info ) use ( $blacklist_sender, $blacklist_receiver, $DEBUG_HEADERS ) {
 
 	# The following code is under Apache license (c) Phabricator, Phacility
 	# https://secure.phabricator.com/source/phabricator/browse/master/scripts/mail/mail_handler.php
 	# https://secure.phabricator.com/source/phabricator/browse/master/LICENSE
 
 	// complete message
 	$message = $headers . $body;
 
 	$parser = new MimeMailParser();
 	$parser->setText( $message );
 
 	$content = array();
 	foreach (array('text', 'html') as $part) {
 	  $part_body = $parser->getMessageBody($part);
 
 	  if (strlen($part_body) && !phutil_is_utf8($part_body)) {
 	    $part_headers = $parser->getMessageBodyHeaders($part);
 	    if (!is_array($part_headers)) {
 	      $part_headers = array();
 	    }
 	    $content_type = idx($part_headers, 'content-type');
 	    if (preg_match('/charset="(.*?)"/', $content_type, $matches) ||
 	        preg_match('/charset=(\S+)/', $content_type, $matches)) {
 	      $part_body = phutil_utf8_convert($part_body, 'UTF-8', $matches[1]);
 	    }
 	  }
 
 	  $content[$part] = $part_body;
 	}
 
 	// parse the email headers
 	$headers = $parser->getHeaders();
 	$headers['subject'] = phutil_decode_mime_header($headers['subject']);
 	$headers['from'] = phutil_decode_mime_header($headers['from']);
 
+	// debug mail headers
+	if( $DEBUG_HEADERS ) {
+		foreach( $headers as $header => $value ) {
+
+			// simplify message
+			if( is_array( $value ) ) {
+				$value = implode( ', ', $value );
+			}
+
+			message( sprintf( "HEADER %s: %s", $header, $value ) );
+		}
+	}
+
 	// shortcut for the "From:" email address
-	$from = $headers['from'];
+	$from = $headers['from'] ?? '';
+
+	// shortcut for the "To:" email address
+	$to = $headers['to'] ?? '';
 
 	/*
 	 * Check if the "From:" email address is blacklisted
 	 *
+	 * Also, it checks if the address is in the "To:" address.
+	 * This is useful for mailing lists where the email is sent From a normal user but the
+	 * "To:" is the mailing list itself, while every member receives the email.
+	 *
 	 * Actually the comparison is strict because this is not intended to fight spam
 	 * anyway feel free to add a regex or something like that.
 	 */
-	if( $sender_blacklist && is_from_blacklisted( $from, $sender_blacklist ) ) {
+	if( $blacklist_sender && is_address_blacklisted( $from, $blacklist_sender ) ) {
+
+		// show in the log that this email will be discarded
+		message( "delete blacklisted from $from" );
+
+		// just mark this message for deletion and skip further processing
+		return true;
+	}
+
+	if( $blacklist_receiver && is_address_blacklisted( $to, $blacklist_receiver ) ) {
 
 		// show in the log that this email will be discarded
-		message( "delete blacklisted $from" );
+		message( "delete blacklisted to $to" );
 
 		// just mark this message for deletion and skip further processing
 		return true;
 	}
 
 	// log the processed email addresses just for fun
 	message( "process $from" );
 
 	$received = new PhabricatorMetaMTAReceivedMail();
 	$received->setHeaders($headers);
 	$received->setBodies($content);
 
 	$attachments = array();
 	foreach ($parser->getAttachments() as $attachment) {
 	  if (preg_match('@text/(plain|html)@', $attachment->getContentType()) &&
 	      $attachment->getContentDisposition() === 'inline') {
 	    // If this is an "inline" attachment with some sort of text content-type,
 	    // do not treat it as a file for attachment. MimeMailParser already picked
 	    // it up in the getMessageBody() call above. We still want to treat 'inline'
 	    // attachments with other content types (e.g., images) as attachments.
 	    continue;
 	  }
 
 	  $file = PhabricatorFile::newFromFileData(
 	    $attachment->getContent(),
 	    array(
 	      'name' => $attachment->getFilename(),
 	      'viewPolicy' => PhabricatorPolicies::POLICY_NOONE,
 	    ));
 	  $attachments[] = $file->getPHID();
 	}
 
 	$delete = true;
 
 	try {
 	  $received->setAttachments($attachments);
 	  $received->save();
 	  $received->processReceivedMail();
 	} catch (Exception $e) {
 
 	  // delete messages with errors because Phabricator can reply to the sender
 	  // $delete = false;
 
 	  // if Phabricator detects an exection, contact the sender with that message
 	  $received
 	    ->setMessage(pht('EXCEPTION: %s', $e->getMessage()))
 	    ->save();
 
 	  // log some errors
 	  message( $e->getMessage() );
 	}
 
 	return $delete;
 } );
 
 // flag indicating that an error raised
 $error = false;
 
 // flag indicating that we can continue to scan again the mailbox
 $loop = true;
 
 // let's go
 message( "started" );
 
 do {
 	try {
 		// open the connection
 		$spooler->open();
 
 		// just process all and then quit
 		$spooler->processAll();
 
 		// close the connection
 		$spooler->close();
 
 		// wait some time
 		sleep( IMAPBOT_CYCLE_SLEEP );
 
 	} catch( Exception $e ) {
+
 		printf(
 			"Phabricator SMTP bot error (%s): %s\n",
 			get_class( $e ),
 			$e->getMessage()
 		);
 
+		printf(
+			"  Trace: %s\n",
+			$e->getTraceAsString()
+		);
+
 		// we can't just stop looping because sometime the user sends a wrong command and we get an Exception
 		// $loop  = false;
 
 		$error = true;
 	}
 
 } while( $loop );
 
 /**
  * Operating system signal handler
  *
  * @param $signo   int
  * @param $siginfo mixed
  */
 function sig_handler( $signo, $siginfo ) {
 
 	// stop looping
 	$GLOBALS['loop'] = false;
 
 	// eventually close the spooler
 	$GLOBALS['spooler']->close();
 
 	// just warn about this signal
 	message( "quit after SIG $signo" );
 
 	// quit
 	if( $GLOBALS['error'] ) {
 		exit( 1 );
 	} else {
 		exit( 0 );
 	}
 }
 
 /**
  * Print a message to standard output with a date
  *
  * @param string $message
  */
 function message( $message ) {
 	printf( "[%s] %s\n", date( 'c' ), $message );
 }
 
 /**
  * Check if a "From:" email address matches the blacklisted ones
  *
- * @param  string $from      Something like 'Foo Bar <foo@bar.com>'
+ * @param  string $addresses Something like 'Foo Bar <foo@bar.com>'
  * @param  array  $blacklist Array of blacklisted email addresses
  * @return boolean
  */
-function is_from_blacklisted( $from, $blacklist ) {
+function is_address_blacklisted( $addresses, $blacklist ) {
 
 	// parse the "From:" email addresses
-	$addresses = mailparse_rfc822_parse_addresses( $from );
-	foreach( $addresses as $address ) {
-		list( $display, $address, $is_group ) = $address;
+	$emails_data = mailparse_rfc822_parse_addresses( $addresses );
+	foreach( $emails_data as $email_data ) {
+
+		// address infos
+		$display  = $email_data['display'];
+		$email    = $email_data['address'];
+		$is_group = $email_data['is_group'];
 
 		// check if the email address exactly matches one in the blacklist
-		if( in_array( $address, $blacklist, true ) ) {
+		if( in_array( $email, $blacklist, true ) ) {
 			return true;
 		}
 	}
 
 	return false;
 }
diff --git a/config-example.php b/config-example.php
index 01d2b9a..9664734 100644
--- a/config-example.php
+++ b/config-example.php
@@ -1,27 +1,31 @@
 <?php
 # remember to copy this file, fill, and save as 'config.php'
 
 # path to your Phabricator installation
 define( 'IMAPBOT_PATH_PHAB', '/path/to/phabricator' );
 
 # your mailbox connection URL
 # see the full syntax in https://www.php.net/manual/en/function.imap-open.php
 define( 'IMAPBOT_IMAP_MAILBOX', '{HOST:PORT/ssl}INBOX' ); // HOST example: foo.it,   PORT example: 993
 
 # your mailbox username
 define( 'IMAPBOT_IMAP_USERNAME', 'foo@bar.it' );
 
 # your mailbox password
 define( 'IMAPBOT_IMAP_PASSWORD', 'imap password password' );
 
 # how much seconds to wait before checking new e-mails
 define( 'IMAPBOT_CYCLE_SLEEP', 10 );
 
 # path to the IMAPSpooler class (maybe you can leave this as-is)
 define( 'IMAPBOT_PATH_SPOOLER',  __DIR__ . '/../php-imap-spooler/class-IMAPSpooler.php' );
 
 # add some other configurations like sender blacklist
 $IMAPBOT = new stdclass();
 $IMAPBOT->SENDER_BLACKLIST = [
-	'very-spammy-address@example.com',
+//	'very-spammy-address@example.com',
+];
+
+$IMAPBOT->RECEIVER_BLACKLIST = [
+//	'very-mailing-list@example.com',
 ];