Block attaching documents

Laxson Paradza 20 Reputation points
2023-11-28T13:43:01.42+00:00

Is there a way to disable attachments while sending documents in Outlook, both desktop and online, and only allow links to be sent?

Microsoft 365
Microsoft 365
Formerly Office 365, is a line of subscription services offered by Microsoft which adds to and includes the Microsoft Office product line.
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Outlook
Outlook
A family of Microsoft email and calendar products.
3,371 questions
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  1. Yuki Sun-MSFT 41,011 Reputation points
    2023-11-29T02:10:31.9833333+00:00

    Hi @Laxson Paradza ,

    Is there a way to disable attachments while sending documents in Outlook, both desktop and online, and only allow links to be sent?

    You can create a mail flow rule similar like blow to block mails with attachments from being sent:
    User's image

    Tick "Stop processing more rules" after clicking Next:
    User's image

    From the Exchange admin center, we can only set the attachment size limit to "1KB", to block smaller attachments as well, we'll need to connect to Exchange Online PowerShell and run the command below:

    Set-TransportRule -Identity <RuleName> -AttachmentSizeOver 1B
    
    

    User's image

    I tried testing in my lab tenant and below is the NDR I received when attempting to send out a mail with an attachment(1byte):
    User's image


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