question

GonWild-8986 avatar image
0 Votes"
GonWild-8986 asked YukiSun-MSFT answered

Office Message Encryption - Recipient not able to open office attachments

Hello,
I'm testing the implementation of OME in our organization, and I have a question:

Sending a word/excel attachment in an encrypted email to a recipient with no Microsoft 365 subscription, results in recipient not able to open the file. The preview function in the browser for viewing the encrypted message is able to view the file, but downloading and trying to open/edit the file fails. Opening a excel file in XLS viewer or older local office version triggers RMS saying he doesn't have persmission to the document.

Is this by design, or am I doing something wrong? What are the requirements for sending OME encrypted office-file attachments to external recipients?


office-exchange-server-mailflowoffice-online-server-exchange
5 |1600 characters needed characters left characters exceeded

Up to 10 attachments (including images) can be used with a maximum of 3.0 MiB each and 30.0 MiB total.

michev avatar image
1 Vote"
michev answered GonWild-8986 commented

This is by design, as protection is embedded in the file itself. If you want them to be able to download attachments in unencrypted form, use the configuration detailed here: https://techcommunity.microsoft.com/t5/microsoft-security-and/admin-control-for-attachments-now-available-in-office-365/ba-p/204007

· 1
5 |1600 characters needed characters left characters exceeded

Up to 10 attachments (including images) can be used with a maximum of 3.0 MiB each and 30.0 MiB total.

Perfect, this is spot on. Thanks!

1 Vote 1 ·
YukiSun-MSFT avatar image
0 Votes"
YukiSun-MSFT answered

Hi @GonWild-8986,

As michev said, by default the attachments in an encrypted message remain protected when downloaded. To allow recipients to download Encrypt-only attachments without encryption, please refer to the article shared by michev:

 Set-IRMConfiguration - DecryptAttachmentForEncryptOnly $true

And here is another official link for your reference: To manage whether email attachments are decrypted on download from a web browser


If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.



5 |1600 characters needed characters left characters exceeded

Up to 10 attachments (including images) can be used with a maximum of 3.0 MiB each and 30.0 MiB total.