Hi guys,osTicket (v1.9.11) on NginxExcept Nginx, almost all settings vanilla. MTA is postfix, mail is fetched from dovecot via IMAP by /etc/crontab.Email clients: Thunderbird, Android Mail App, Outlook 2010/13, Roundcube Webmail, Horde Webmail, ...Typical workflow:A customer sends an email with a new issue to my email address. I forward this email to the osTicket instance and wait for the reply with the ticket number. Then I reply to the customers original mail, but with #NNN, , or at the end of the header and CC to osTicket. Sometimes this creates new tickets, sometimes it matches the tickets.If the customer replys to this email with the ticket number in the subject, it sometimes works and sometimes not. I see no correlation with the format of the ticket number, it looks random.I bolded some words because in my workflow some information in the email header that osTicket relies on might get lost.I'm testing osTicket since three weeks now with one customer, 8 users and two agents. Almost 5030% of the 3043 tickets are duplicates right now. The email feature was not active in the first week and older tickets that have been edited only via the webinterface are ok.Edt: Almost all problematic tickets belong to a guest user with my email address, he has 20 open tickets. My agent account uses the same email address, but as I understand the db table structure, user and agent are completly different.