diff -urN ../roundcubemail-1.5.2.orig/program/lib/Roundcube/rcube_imap_generic.php ./program/lib/Roundcube/rcube_imap_generic.php
--- ../roundcubemail-1.5.2.orig/program/lib/Roundcube/rcube_imap_generic.php	2021-12-30 00:29:24.000000000 +0200
+++ ./program/lib/Roundcube/rcube_imap_generic.php	2022-05-12 18:58:41.693706000 +0300
@@ -2589,18 +2589,25 @@
                             $result[$id]->timestamp = rcube_utils::strtotime($string);
                             break;
                         case 'to':
-                            $result[$id]->to = preg_replace('/undisclosed-recipients:[;,]*/', '', $string);
+//                            $result[$id]->to = preg_replace('/undisclosed-recipients:[;,]*/', '', $string);
+                            $result[$id]->to = (empty($result[$id]->to) ? '' : $result[$id]->to . ', ') . preg_replace('/undisclosed-recipients:[;,]*/', '', $string);
                             break;
                         case 'from':
                         case 'subject':
                             $string = substr($string, 0, 2048);
-                        case 'cc':
-                        case 'bcc':
+                            if (empty($result[$id]->{$field})) $result[$id]->{$field} = $string;
+                            break;
                         case 'references':
                             $result[$id]->{$field} = $string;
                             break;
+                        case 'cc':
+                        case 'bcc':
+//                            $result[$id]->{$field} = $string;
+                            $result[$id]->{$field} = (empty($result[$id]->{$field}) ? '' : $result[$id]->{$field} . ', ') . $string;
+                            break;
                         case 'reply-to':
-                            $result[$id]->replyto = $string;
+//                            $result[$id]->replyto = $string;
+                            $result[$id]->replyto = (empty($result[$id]->replyto) ? '' : $result[$id]->replyto . ', ') . $string;
                             break;
                         case 'content-transfer-encoding':
                             $result[$id]->encoding = substr($string, 0, 32);