Outlook PST Files – Ingestion Considerations…


In most of the legacy Exchange deployments, users historically have archived e-mails to prevent their mailbox from filling up within Outlook due to lack of proper archive strategies. These archived files, also known as Personal Folders or PSTs, have traditionally been stored on the user’s workstation local drive or on the network. 

As with any Exchange transformation, introduction of a 3rd party archive or Exchange native archive capabilities, PSTs are longer required.  However, old email data is critical and PST Ingestion becomes a major project. There are quite a few benefits of PST Ingestion in to a 3rd party archive or Exchange Native Archive like – Storage costs, Costs of PST recovery, PST Management, Compliance to regulations etc.

As a starting point, there are a multiple scenarios that need to be factored for the PST ingestion.

Key decisions based upon PST Source

Source Strategic direction
User mailbox Ingest to 3rd party archive like Enterprise Vault
Leaver mailbox Do not migrate – backup to tape and delete
Shared/team mailbox Ingest to shared 3rd party archive like EV
Exec mailbox Ingest to 3rd party archive like EV

Some key decisions based upon PST type..

PST type Strategic direction
User mailbox Ingest to 3rd party archive like EV
Normal PST files Ingest to 3rd party archive like EV
Password protected Strip password and ingest
Corrupt PSTs Manually validate and exclude from migration
Empty PSTs Do not migrate
Orphaned PSTs Do not migrate – backup to tape and delete

Key PST Policies to factor

Policies Strategic direction
Item types User email
Age of items Default – user emails <= 2 years.
Executives/exceptions – user emails <= 7 years
Retention 7 years or as per organization policies
Deletion of source PST On successful completion of PST ingestion
– Notification to end user.
– Deletion of PST after 30 days or as agreed

Some key planning items are w.r.t different types of migrations: Local users, High bandwidth sites, Low bandwidth sites, Offline transfer for sites with large volumes of data and/or Mobile user transfer. Along with that another planning item that is critical from a user experience is categorization of User groups into: Silent migration – background migration with no user interaction or User driven migration – Users select the files and time to migrate.

Another critical planning process is defining PST Handling and communication considerations, like:

  • PST Selection process (user driven, opt in/out, no communication)
  • Define handling of password protected files (user communication or automated)
  • Define handling of corrupt PST files (handling/user communication)
  • Define scope of what is imported – how to communicate (all, certain classes, with or without shortcuts)
  • Define handling of “private” non-migrate marked files (burn CD, policy in migration)
  • Define requirements post migration (delete files, set registry keys)
  • Define delete process (backup, end delete, running delete)
  • Define how to handle different languages (communication)
  • Identify and confirm any legal requirements (privacy concerns and the like)

PST ingestion in general is a very straight forward process, however lack of planning or discovery on certain areas increases the effort, some of them are:

  • Network Bandwidth
  • Corrupt PSTs/msgs
  • Password protected
  • Orphaned PSTs
  • Outlook closed
  • User error Management overhead

So, these were veryhigh level considerations that you need to look at from a PST Ingestion. It is generally a good idea to use a 3rd party solution like PST FlightDeck for ingestion, rather than relying on manual processes.

More in coming days….