Reduce the email age threshold for the JEPP cleaner job.

Problem Definition

Currently JIRA Service Desk is keeping emails in its database up to 6 months. This will cause customer's databases (and therefore backups) to grow very fast.

Consequently, this may even impact the performance of JIRA as it, by default, automatically creates backups every 12 hours.

Suggested Solution

Remove emails that are older then 4~6 weeks, which would most likely be already obsolete.

Alternatively, mark the email as "already processed" when it is processed, and delete those entries with the cleaner job.