Reply emails being processed as NewIssue An email has received to the instance with all required properties to consider as Reply, instead its marked as New and Inbound actions for NEW had runReleaseALLCauseAn email has received with Subject contains the prefix as RE, contains a valid active Record and also a valid watermark. Though its considered as NEW instead of Reply Eg of subject: RE:INC00011 updated This DOC has explained well the email flow and how the instance determine the type of incoming email But in this particular situation, the user who is sending the reply email is not having access to the record mentioned in the subject or associated watermark. You can check this by either Impersonate and check or else try the below background script =========== var user_sys_id = "bcb398111bbc48103a19646fad4bcba4"; // sys-id of the uservar my_User = gs.getUserID();var g_sesh = GlideSession.get();g_sesh.impersonate(user_sys_id);gs.print("Impersonating "+gs.getUser().name);var user = gs.getSession().getUser();var grs = new GlideRecordSecure('incident');grs.addQuery('number','INC0162029'); // Number came in the Subjectgrs.query();if(grs.next()){gs.print("Short description. "+grs.short_description)}gs.print("QUERY COMPLETED");g_sesh.impersonate(my_User) ===========ResolutionAdd proper role to the user to view and write the record by setting/modifying an ACL