Office of Information Technology

The purpose of the Email Retention Guide is to familiarize the University employee community with the current Microsoft 365 email retention policies while providing guidance on available options for managing, retaining, and safeguarding email records in a supported manner.

Procedures and Responsibilities

The retention settings are designed to comply with the established Standard Administrative Procedures (SAP 29.01.03.10.01, sect. 19.9-19.15), which govern the storage of email on the central mail system. The complete Standard Administrative Procedure (SAP) may be found at:

TAMIU Rules and SAP's

SAP 29.01.03.L0.01

Email Retention

As required by SAP 29.01.03.10.01, TAMIU has established the following retention policies for mailboxes stored on the University's Microsoft 365 email system.

Primary Mailbox Retention

Previous Policy

• Email messages older than 30 days were automatically deleted from Inbox, Sent Items, Junk Email, and other mailbox folders.

Current Policy

• Email messages are no longer automatically deleted based on age from:
  • Inbox
  • Sent Items
  • Drafts
  • User-created folders and subfolders
  • Other standard mailbox folders

Users may retain email messages in their primary mailbox as long as mailbox storage limits are not exceeded.

Deleted Items and Junk Email Retention

Email messages in the following folders will be automatically deleted after 30 days:

• Deleted Items
• Junk Email

This replaces the previous policy that permanently deleted messages after 2 days.

Users should periodically review these folders and recover any messages they wish to retain before automatic deletion occurs.

Mailbox Storage Limits

The primary Microsoft 365 mailbox is limited to 100 GB.

While email messages are no longer automatically removed from the mailbox, users remain responsible for managing mailbox storage. Excessive email accumulation may cause mailbox performance issues and eventually prevent sending or receiving new email once mailbox limits are reached.

Users are encouraged to:

• Delete unnecessary email messages.
• Empty Deleted Items regularly.
• Move long-term retention email to the Online Archive.
• Organize mailbox folders to reduce clutter and improve mailbox performance.

Email Retention Options

If there is a need to retain emails beyond the practical limits of the primary mailbox, the online archive is the recommended solution.

Email users are encouraged to consult State of Texas and Texas A&M University System retention schedules to determine which approach best meets their requirements.

Visit the approved System Records Retention Schedule here.

Users with unique retention requirements not addressed in this guide should contact the OIT Help Desk for assistance.

Online Archive / In Place Archive

The Microsoft 365 Online Archive is the University's long-term email retention solution.

Benefits of Online Archive

• Hosted within Microsoft's Office 365 cloud services.
• Backed by Microsoft 365 enterprise storage infrastructure.
• Accessible through:
  • Outlook for Windows
  • Outlook for Mac
  • Outlook on the Web
  • Mobile Outlook applications
• Searchable alongside primary mailbox content.
• Eliminates reliance on local archive files.

Storage Capacity

Online Archive mailboxes begin with 100 GB of storage.

Microsoft 365 Auto-Expanding Archive technology automatically increases archive capacity as needed, providing archive growth up to 1.5 TB.

This allows users to retain large volumes of email without impacting their primary mailbox storage quota.

Using the Online Archive

Users may move or copy email messages directly into the Online Archive mailbox.

Messages can be archived by:

• Moving individual emails
• Moving groups of emails
• Creating Outlook rules
• Using retention policies where available

Because archived content remains in Microsoft 365, it remains accessible from any supported Outlook client.

Microsoft Outlook Client

Outlook on the Web

iOS/Android

Local Archive (PST Files / On My Computer Files)

As of September 25, 2026 the University is no longer storing new emails in local archive files.

Users who currently have local archive files should continue to store those files in local storage and should not move them into the Online Archive.

Important Considerations

Local archive files:

• Are stored on a local computer or network location.
• Are not part of Microsoft 365 cloud services.
• Are generally not protected by Microsoft 365 retention and recovery capabilities.
• May be inaccessible if the local workstation fails.
• May be permanently lost if no separate backup exists.

Recommendation

The Office of Information Technology recommends that Local Archive (.PST) files or Outlook "On My Computer" folders remain in local storage.

These files should not be moved into the Online Archive.

For ongoing email storage and archiving, the Online Archive is the preferred solution as it provides greater reliability, accessibility, recoverability, and storage capacity than local archive files.

FAQs

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