Onna offers a mirror sync for Slack Enterprise that will mirror any retention policy set within your organization's Slack account. If you choose to enable mirror sync, any messages that are removed from Slack due to a retention policy will now be removed from Onna as well, unless that information is under legal hold.
Note: This feature can only be accessed by admins and is set to affect all Slack Enterprise sources across your Onna environment. Onna will mirror the setting that it finds locally within Slack Enterprise and will obey it at whatever level its found. Multiple retention settings in a Slack Enterprise Grid or Slack Enterprise Workspace can coexist in the same source or across different sources in Onna. If you have Slack Enterprise sources that are running as legal holds, please make sure they are also on legal hold in Onna.
How to Enable Mirroring of Slack Retention Policies in Onna
As an admin, expand the options available on the left hand menu. Click on 'Admin Preferences.'
There will be three sections available. Click on Sources, Sources Configuration, and then select the option to Mirror Slack Enterprise Retention Settings.
Note: Before selecting this option, make sure that all Slack Enterprise sources that are running legal holds are also placed on legal hold in Onna.
Once checked, this will go through all Slack Enterprise sources that are on 'Auto-sync and archive' on the global account to make sure they all comply with the retention policies found within Slack. Any messages and attachments that are no longer retained in Slack will not be retained in Onna within 24 hours of their dropping out of Slack.
Note: This setting will not apply to Slack Enterprise sources that are on one-time sync.