Cal Poly's DocuSign account has a "purge" feature enabled that removes envelopes from the system 90 days after they have been Completed, Voided, or Declined.
This feature is enabled to protect all Cal Poly DocuSign users and their documents and follows the Standards on the Appropriate Use of DocuSign that were established by Cal Poly as a security best practice.
Senders and recipients alike will receive email notifications warning them when an envelope is approaching its 90 day limit and has been scheduled for deletion. Envelopes that have been purged can not be recovered - these notifications are to ensure that if either party wants to keep a copy of the envelope they have the opportunity to do so by downloading it.
If you wish to disable these notifications, you can review the Managing DocuSign Email Notifications page.