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Guidelines For Cleaning Out Your .PST and Your Mailbox

Before moving your .pst to your mailbox or requesting a larger mailbox quota, you should delete all out-of-date and irrelevant messages. Please take the steps below to reduce the size of your Outlook mailbox:

  1. Delete messages that have met their records retention requirements and all non-record messages that are no longer current or relevant. For information on the retention requirements for specific records, see the Records Retention Guide at:

    Messages that are not records and can be deleted when they are no longer useful include:

    1. Resources material – material that has been created or received for reference purposes
    2. General routine department business correspondence – messages that have short-term administrative or operation value used to provide information or for the completion of a request or action such as:
      1. routine requests for information
      2. meeting notices and reminders
      3. administrative notices
      4. invitations and responses
      5. interoffice activities
      6. “while you were out” messages
    3. Draft documents
    4. Courtesy copy informational messages – messages you receive to keep you informed on a matter, but you do not need to act on.
  2. Attachments, particularly the larger ones, can take up large amounts of storage in Outlook. Sort your messages by attachment size, and take the following steps:
    1. Delete all messages with attachments that are no longer needed or do not contain records.
    2. If the content of the email message is not needed to complete the record, move the attachments to the appropriate folder on your network or hard drive; then delete the original message from Outlook.
    3. If the email message has additional information, and/or the recipients of the message, or the date and time the message was sent are important; then keep the email and the attachment in your mailbox. Keep only the message with the final version of the attachment in your mailbox.
  3. If you have multiple messages on the same topic with the same subject (message thread), delete all of the messages except for the final message which contains all of the previous messages.
  4. Forward all personal messages and photographs/attachments to a personal email account, then delete the originals from Outlook. If you do not have a personal email account, you can save them on removable media before deleting them from Outlook.
  5. Set the delete folder to empty when you exit Outlook.
  6. Move email records out of the “Sent Items” folder into appropriate folders and delete all remaining messages.
  7. Complete or delete messages in the “Drafts” folder.
  8. Delete messages in the “Junk E-mail” folder.

Reviewed 2019-08-05