Outlook blocked access to potentially unsafe attachments [FIX]

Tashreef Shareef
by Tashreef Shareef
Windows & Software Expert
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3 Ways to Fix attachment blocking Message

Many users have reported a strange message on their Outlook client’s menu reading Outlook blocked access to the following potentially unsafe attachments. This message appears when the users try to open an email with attachments. This can happen due to many reasons including attachments that did not follow official attachment guidelines and if the attachment appears to be a malware code.

If you are also troubled by this error, here is how to fix this error message in the Outlook client.


How do I unblock unsafe attachments in Outlook?

1. Change Outlook Security using Registry Editor

  1. Press Windows Key + R to open Run.
  2. Type Regedit in the Run box and press OK to open the Registry Editor.
  3. In the Registry Editor, navigate to the following location.
  4. Now click on the Office version installed on your system. In my case, it is Office 16.0.
  5. Under the Office version, expand the Outlook key.
  6. Right-click on Outlook key and select New > Key.
    new key registry outlook blocked access to the following potentially unsafe attachments
  7. Rename the newly created key as Security.
  8. Select the Security key. In the right-pane, right-click on an empty space and select New > String Value.new string value outlook blocked access to the following potentially unsafe attachments
  9. Rename the newly string value as Level1Remove and press Enter.
  10. Now double-click on Level1Remove.
  11. In the Edit String window, you need to enter the extension format that you want to exclude from the Microsoft Outlook security check.
    value data outlook blocked access to the following potentially unsafe attachments
  12. So, if you want to receive .js and .exe files in the attachment without any message, then enter .js;.exe;
  13. Click OK to save the changes.
  14. Close the registry editor and open Outlook and check if the message still appears.

The best format to send email attachments is a zip archive. Learn how to zip files and folders with these guides.

2. Receive the File through Third-party File Sharing Service

  1. One way to make this message disappear is to turn it off from the Registry Editor for outlook. However, that should be your last option.file sharing services outlook blocked access to the following potentially unsafe attachments
  2. The best thing to do is to ask the sender to upload the attachment to any third-party file sharing sites like Google Drive or Dropbox and then share the sharable file link via email.
  3. You can then easily download the file to your computer directly from the Cloud hosting services.
  4.  This way you don’t need to disable the security feature for Microsoft Outlook and also receive the file without any restrictions.

3. Receive Attachment in Compressed Format

  1. Another workaround to skip the security check-in Microsoft Outlook is to receive the file in compressed format.
  2. You can make use of any free file compression tool like WinRar or 7Zip to do the same.7zip outlook blocked access to the following potentially unsafe attachments
  3. Whether you are sending the attachment or receiving it, if it includes any executable files, make sure it compressed using the above-mentioned tools.