diff --git a/composer.json b/composer.json
index 82da669a..e4dd7ddd 100644
--- a/composer.json
+++ b/composer.json
@@ -56,7 +56,8 @@
         "league/oauth2-google": "Needed for Google XOAUTH2 authentication",
         "psr/log": "For optional PSR-3 debug logging",
         "thenetworg/oauth2-azure": "Needed for Microsoft XOAUTH2 authentication",
-        "symfony/polyfill-mbstring": "To support UTF-8 if the Mbstring PHP extension is not enabled (^1.2)"
+        "symfony/polyfill-mbstring": "To support UTF-8 if the Mbstring PHP extension is not enabled (^1.2)",
+        "ext-imap": "Needed to support advanced email address parsing according to RFC822"
     },
     "autoload": {
         "psr-4": {
diff --git a/language/phpmailer.lang-es.php b/language/phpmailer.lang-es.php
index 4e74bfb7..35ce5b8e 100644
--- a/language/phpmailer.lang-es.php
+++ b/language/phpmailer.lang-es.php
@@ -9,7 +9,7 @@
  */
 
 $PHPMAILER_LANG['authenticate']         = 'Error SMTP: Imposible autentificar.';
-$PHPMAILER_LANG['buggy_php']            = 'Tu versión de PHP está afectada por un bug que puede resultar en mensajes corruptos. Para arreglarlo, cambia a enviar usando SMTP, deshabilita la opción mail.add_x_header en tu php.ini, cambia a MacOS o Linux, o actualiza tu PHP a la versión 7.0.17+ o 7.1.3+.';
+$PHPMAILER_LANG['buggy_php']            = 'Tu versión de PHP ha sido afectada por un bug que puede resultar en mensajes corruptos. Para arreglarlo, cambia a enviar usando SMTP, deshabilita la opción mail.add_x_header en tu php.ini, cambia a MacOS o Linux, o actualiza tu PHP a la versión 7.0.17+ o 7.1.3+.';
 $PHPMAILER_LANG['connect_host']         = 'Error SMTP: Imposible conectar al servidor SMTP.';
 $PHPMAILER_LANG['data_not_accepted']    = 'Error SMTP: Datos no aceptados.';
 $PHPMAILER_LANG['empty_message']        = 'El cuerpo del mensaje está vacío.';
@@ -18,7 +18,7 @@ $PHPMAILER_LANG['execute']              = 'Imposible ejecutar: ';
 $PHPMAILER_LANG['extension_missing']    = 'Extensión faltante: ';
 $PHPMAILER_LANG['file_access']          = 'Imposible acceder al archivo: ';
 $PHPMAILER_LANG['file_open']            = 'Error de Archivo: Imposible abrir el archivo: ';
-$PHPMAILER_LANG['from_failed']          = 'La(s) siguiente(s) direcciones de remitente fallaron: ';
+$PHPMAILER_LANG['from_failed']          = 'La siguiente dirección de remitente falló: ';
 $PHPMAILER_LANG['instantiate']          = 'Imposible crear una instancia de la función Mail.';
 $PHPMAILER_LANG['invalid_address']      = 'Imposible enviar: dirección de email inválido: ';
 $PHPMAILER_LANG['invalid_header']       = 'Nombre o valor de encabezado no válido';
@@ -34,3 +34,4 @@ $PHPMAILER_LANG['smtp_connect_failed']  = 'SMTP Connect() falló.';
 $PHPMAILER_LANG['smtp_detail']          = 'Detalle: ';
 $PHPMAILER_LANG['smtp_error']           = 'Error del servidor SMTP: ';
 $PHPMAILER_LANG['variable_set']         = 'No se pudo configurar la variable: ';
+$PHPMAILER_LANG['imap_recommended']     = 'No se recomienda usar el analizador de direcciones simplificado. Instala la extensión IMAP de PHP para un análisis RFC822 más completo.';
diff --git a/src/PHPMailer.php b/src/PHPMailer.php
index 5b0ba5c0..5388f4fc 100644
--- a/src/PHPMailer.php
+++ b/src/PHPMailer.php
@@ -1280,47 +1280,65 @@ class PHPMailer
             }
         } else {
             //Use this simpler parser
-            $list = explode(',', $addrstr);
-            foreach ($list as $address) {
-                $address = trim($address);
-                //Is there a separate name part?
-                if (strpos($address, '<') === false) {
-                    //No separate name, just use the whole thing
-                    if (static::validateAddress($address)) {
-                        $addresses[] = [
-                            'name' => '',
-                            'address' => $address,
-                        ];
-                    }
-                } else {
-                    list($name, $email) = explode('<', $address);
-                    $email = trim(str_replace('>', '', $email));
-                    $name = trim($name);
-                    if (static::validateAddress($email)) {
-                        //Check for a Mbstring constant rather than using extension_loaded, which is sometimes disabled
-                        //If this name is encoded, decode it
-                        if (defined('MB_CASE_UPPER') && preg_match('/^=\?.*\?=$/s', $name)) {
-                            $origCharset = mb_internal_encoding();
-                            mb_internal_encoding($charset);
-                            //Undo any RFC2047-encoded spaces-as-underscores
-                            $name = str_replace('_', '=20', $name);
-                            //Decode the name
-                            $name = mb_decode_mimeheader($name);
-                            mb_internal_encoding($origCharset);
-                        }
-                        $addresses[] = [
-                            //Remove any surrounding quotes and spaces from the name
-                            'name' => trim($name, '\'" '),
-                            'address' => $email,
-                        ];
-                    }
-                }
-            }
+            $addresses = self::parseSimplerAddresses($addrstr, $charset);
         }
 
         return $addresses;
     }
 
+    /**
+     * Parse a string containing one or more RFC822-style comma-separated email addresses
+     * of the form "display name <address>" into an array of name/address pairs.
+     * Uses a simpler parser that does not require the IMAP extension but doesnt support
+     * the full RFC822 spec. For full RFC822 support, use the PHP IMAP extension.
+     *
+     * @param string $addrstr The address list string
+     * @param string $charset The charset to use when decoding the address list string.
+     *
+     * @return array
+     */
+    protected static function parseSimplerAddresses($addrstr, $charset)
+    {
+        // Emit a runtime notice to recommend using the IMAP extension for full RFC822 parsing
+        trigger_error(self::lang('imap_recommended'), E_USER_NOTICE);
+        $list = explode(',', $addrstr);
+        foreach ($list as $address) {
+            $address = trim($address);
+            //Is there a separate name part?
+            if (strpos($address, '<') === false) {
+                //No separate name, just use the whole thing
+                if (static::validateAddress($address)) {
+                    $addresses[] = [
+                        'name' => '',
+                        'address' => $address,
+                    ];
+                }
+            } else {
+                list($name, $email) = explode('<', $address);
+                $email = trim(str_replace('>', '', $email));
+                $name = trim($name);
+                if (static::validateAddress($email)) {
+                    //Check for a Mbstring constant rather than using extension_loaded, which is sometimes disabled
+                    //If this name is encoded, decode it
+                    if (defined('MB_CASE_UPPER') && preg_match('/^=\?.*\?=$/s', $name)) {
+                        $origCharset = mb_internal_encoding();
+                        mb_internal_encoding($charset);
+                        //Undo any RFC2047-encoded spaces-as-underscores
+                        $name = str_replace('_', '=20', $name);
+                        //Decode the name
+                        $name = mb_decode_mimeheader($name);
+                        mb_internal_encoding($origCharset);
+                    }
+                    $addresses[] = [
+                        //Remove any surrounding quotes and spaces from the name
+                        'name' => trim($name, '\'" '),
+                        'address' => $email,
+                    ];
+                }
+            }
+        }
+    }
+
     /**
      * Set the From and FromName properties.
      *
@@ -2433,6 +2451,8 @@ class PHPMailer
             'smtp_error' => 'SMTP server error: ',
             'variable_set' => 'Cannot set or reset variable: ',
             'no_smtputf8' => 'Server does not support SMTPUTF8 needed to send to Unicode addresses',
+            'imap_recommended' => 'Using simplified address parser is not recommended. ' .
+                'Install the PHP IMAP extension for full RFC822 parsing.',
         ];
         if (empty($lang_path)) {
             //Calculate an absolute path so it can work if CWD is not here