Upgrade from RT 4.0.6. a new ticket number is created when someone replies to a ticket


I have this strange problem that sometimes occurs and sometimes doesn’t occur. I looked at other similar threads but am not sure where to start to troubleshoot it on our installation. We are running RT 4.0.6 on CentOS release 6.9 (Final). Any advice on how to go about troubleshooting or fixing this? Also how would we upgrade from RT 4.0.6 to the latest version. Any how to guides or problems we might run into? Any help is much appreciated.

Thank you.

By default, RT will use $rtname to match the subject lines of inbound emails. if $rtname changed when you upgraded, replies to emails generated with the old value of $rtname will not be seen as originating from your RT instance.

RT has second variable called $EmailSubjectTagRegex defined in /opt/rt4/etc/RT_Config.pm, and possibly overridden in /opt/rt4/etc/RT_SiteConfig.pm. This can be used to capture emails using either current or old values of $rtname,

See Incoming mail gateway for details.