Applies ToOutlook for Microsoft 365 Outlook 2024 Outlook 2021 Outlook 2019 Outlook 2016 Office for business Office 365 Small Business Microsoft 365 admin

You can restrict permission to content in email messages in Outlook with Information Rights Management (IRM), just as you can restrict permission to other Microsoft Office files.

Important: If you're using Office on a Surface RT device, you can view IRM-protected mail, but you can’t send. Want to see what version of Office you're using?

Information Rights Management (IRM) allows you to specify access permissions to email messages. IRM helps prevent sensitive information from being read, printed, forwarded, or copied by unauthorized people. IRM also helps organizations enforce corporate policy governing the control and dissemination of confidential or proprietary information, both within the organization and with customers and partners.

After permission for a message is restricted by using IRM, the access and usage restrictions are enforced regardless of where the message goes, because the permissions to access an email message are saved in the message file itself.

Note: IRM can’t prevent content from being erased, stolen, corrupted, or captured and transmitted by malicious programs or computer viruses. It also can’t prevent restricted content from being hand-copied or retyped, or prevent a digital photograph or screen capture being taken of the restricted content.

A message with restricted permissions will have a lock icon shown in the message list.

The first time that you try to open an email message that uses restricted permission, you are connected to a licensing server. If the licensing server verifies your credentials, it issues a use license, which defines the level of access that you have to a file. This process is required for each file that uses restricted permission. In other words, content with restricted permission can’t be opened if the licensing server hasn’t issued you a use license for that content.

View messages when IRM isn’t available

If you must read or open content with restricted permission but Outlook isn’t available on the computer that you are using, you can use a web browser. If you use Outlook on the web or Outlook Web App (OWA), you can view restricted messages on any browser.

Remove IRM from a message you've sent

If you're the original sender of a message and you'd like to remove the restricted permissions, use the following steps.

  1. Open the encrypted message from your Sent Items folder by double-clicking it.

  2. Select File > Encrypt > Unrestricted Access.

  3. Select Save.

Notes: 

  • Removing the restricted permissions from a message you've sent will not update the messages in recipients' mailboxes. Only the copy of the message in your Sent Items folder is affected.

  • You cannot remove IRM from a message someone else has sent to you.

File types covered by IRM policies when they are attached to messages

When the following file types are attached to a rights-managed message in Outlook, they are automatically rights-managed. 

Note: If you attach Outlook message files (.msg) to a rights-managed message (such as forwarding multiple Outlook messages within one message), the attached messages aren’t rights managed.

Word documents

File type

Extension

Document

.doc

Document

.docx

Macro-enabled document

.docm

Template

.dot

Template

.dotx

Macro-enabled template

.dotm

Excel documents

File type

Extension

Workbook

.xls

Workbook

.xlsx

Macro-enabled workbook

.xlsm

Template

.xlt

Template

.xltx

Macro-enabled template

.xltm

Non-XML binary workbook

.xlsb

Macro-enabled add-in

.xla

Macro-enabled add-in

.xlam

PowerPoint documents

File type

Extension

Presentation

.ppt

Presentation

.pptx

Macro-enabled presentation

.pptm

Template

.pot

Template

.potx

Macro-enabled template

.potm

Show

.pps

Show

.ppsx

Macro-enabled show

.ppsm

Office theme

.thmx

InfoPath files

File type

Extension

Dynamic Form/Template

.xsn

XPS documents

File type

Extension

XML Paper Specification

.xps

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