Often when a customer sends an email to our support mailbox, duplicate incidents are created within the application.
Oracle Service Cloud
Incidents Created from Ask a Question Page
Duplicate or even triplicate incidents can be created from the Ask a Question page if an end-user clicks the Submit Question or Finish Submitting Question button more than once. In these cases, the content of the incidents will be identical, but the reference number and the timestamp of when the incidents were created will be different.
In cases where multiple incidents are created this way, only one notification will be sent to the assigned staff member since all of the incidents are submitted from the same session. Only the first notification will be sent.
Incidents Created from Email Submittals
When techmail runs, a lock file is put in place to prevent a second occurrence of techmail to run against the mailbox. As a result, there should never be an instance of techmail running twice against your mailbox. Even though there is a lock, duplicate incidents can be created if identical emails exist in the mailbox at the same time during the techmail run. This happens as the checks for duplicates run against the database. Since the emails are identical and have not been committed to the database at this point, both emails will create incidents.
Another possibility for duplicates is if the EGW_DISCARD_DUPLICATE_ENABLED configuration setting is disabled. This setting allows you to discard emails that are determined to be duplicates. If enabled, any email having the same date within four hours, to and from email address (i.e. Sent to the same mailbox from the same sender), subject, and body as an existing incident will be classified as a duplicate message and will be discarded. Default is enabled (Yes). If, however, this setting has been disabled, this would then allow duplicate email messages to create duplicate incidents.
NOTE: Beginning in the May 2015 release, the file attachment name, type, and size is also considered when processing potential duplicate messages. In this same version, the specific mailbox is now ignored as a true duplicate could be sent to multiple configured mailboxes.