Outlook blocked access to the following potentially unsafe attachments

When Outlook blocks an attachment, you can't save, delete, open, print, or otherwise work with the attachment in Outlook. Use one of the methods described below to safely access the attachment:

The first four methods are designed for beginer to intermediate computer users. If these methods don't work for you and if you're comfortable with advanced troubleshooting, use the methods described in the "Advanced troubleshooting" section.

Some methods require to restart your computer.  You may want to print this article first if you choose one of these methods.

General troubleshooting

Method 1: Use a file share to access the attachment

You might want to ask the sender to save the attachment to a server or an FTP site that you can access. Ask the sender to send you a link to the attachment on the server or FTP site. You can click the link to access the attachment and save it on your computer.

If you need help using the server or FTP site, you can ask the sender for help, or you can contact the server administrator for more information.

Method 2: Use a file compression utility to change the file name extension

If no server or FTP site is available to you, you can ask the sender to use a file compression utility, such as WinZip, to compress the file. This creates a compressed archive file that has a different file name extension. Outlook does not recognize these file name extensions as potential threats. Therefore, it does not block the new attachment.

When the sender resends the new attachment to you, you can save it on your computer, and then you can use the third-party file compression software to extract the attachment. If you need help using the third-party file compression software, see your product documentation.

Method 3: Rename the file to have a different file name extension

If third-party file compression software is not available to you, you might want to request that the sender rename the attachment to use a file name extension that Outlook does not recognize as a threat. For example, an executable file that has the file name extension .exe could be renamed as a Word 97 file that has a .doc file name extension.

Ask the sender to resend the renamed attachment to you. After you receive the renamed attachment, you can save it to your computer and rename the file again to use the original file name extension.

Follow these steps to save the attachment and rename it to use the original file name extension:

1. Locate the attachment in the e-mail.
2. Right-click the attachment, and then click Copy.
3. Right-click the desktop, and then click Paste.
4. Right-click the pasted file, and then click Rename.
5. Rename the file to use the original file name extension, such as .exe.

Method 4: Ask the Exchange server administrator to change the security settings

If you use Outlook with a Microsoft Exchange server and the administrator has configured the Outlook security settings, the administrator might be able to help you. Ask the administrator to adjust the security settings on your mailbox to accept attachments such as the one that Outlook blocked.

If these methods did not work for you, and you are comfortable with advanced troubleshooting, please try the steps in the "Advanced troubleshooting" section.

If you are not comfortable with advanced troubleshooting, unfortunately this content is unable to help you any more. For your next steps, you might want to ask someone for help, or you might want to contact Support. For information about how to contact Support, please visit the following Microsoft Web site:

Advanced troubleshooting

If you do not use Outlook with an Exchange server or if the Exchange server administrator lets users change the Outlook attachment security behavior, use method 1: "Customize attachment security behavior."

If you use Outlook with an Exchange server and the Exchange Server administrator has disallowed changes to the Outlook attachment security behavior, use method 2: "Configure Outlook in an Exchange environment."

Method 1: Customize attachment security behavior

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

Important Before you can customize the attachment security behavior in Outlook 2000 SR1 and Microsoft Outlook 2000 SR1a, you must first apply either Microsoft Office 2000 Service Pack 2 or Microsoft Office 2000 Service Pack 3.

Follow these steps to modify the registry and change Outlook's attachment security behavior.

1. Exit Outlook if it is running.
2. Click Start, and then click Run. Copy and paste (or type) the following command in the Open box, and then press ENTER:
   regedit
3. Verify that the following registry key for your version of Outlook exists.
   
   Microsoft Office Outlook 2016
   HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Security
   Microsoft Office Outlook 2013
   HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Security
   Microsoft Office Outlook 2010
   HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security
   Microsoft Office Outlook 2007
   HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Security
   Microsoft Office Outlook 2003
   HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Security
   Microsoft Outlook 2002
   HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Security
   Microsoft Outlook 2000
   HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Outlook\Security
   If the registry key exists, go to step 5.
   
   If the registry key does not exist, follow these steps to create it:
   1. Locate, and then click the following registry key:
      HKEY_CURRENT_USER\Software\Microsoft
   2. Under Edit, click New, and then click Key.
   3. Type Office, and then press ENTER.
   4. Under Edit, click New, and then click Key.
   5. For Outlook 2016, type 16.0, and then press ENTER.
      
      For Outlook 2013, type 15.0, and then press ENTER.
      
      For Outlook 2010, type 14.0, and then press ENTER.
      
      For Outlook 2007, type 12.0, and then press ENTER.
      
      For Outlook 2003, type 11.0, and then press ENTER.
      
      For Outlook 2002, type 10.0, and then press ENTER.
      
      For Outlook 2000, type 9.0, and then press ENTER.
   6. Under Edit, click New, and then click Key.
   7. Type Outlook, and then press ENTER.
   8. Under Edit, click New, and then click Key.
   9. Type Security, and then press ENTER.
4. Under Edit, click New, and then click String Value.
5. Copy and paste (or type) the following name for the new value:
   Level1Remove
6. Press ENTER.
7. Right-click the new string value name, and then click Modify.
8. Type the file name extension of the file type that you want to open in Outlook. For example:
   .exe
   To specify multiple file types, use the following format:
   .exe;.com

Note You must specify the extension without the dot/period such as exe or exe;com in Microsoft 365 versions of Outlook prior to 16.0.12923.10000.  From that version on, Outlook supports file types with or without the dot/period in the extension.

9. Click OK.
10. Exit Registry Editor.
11. Restart your computer.

When you start Outlook, open the file types you specified in the registry.

Note We recommend that you enable only the file types that you have to have. If you rarely receive a particular file type, we recommend that you give Outlook temporary access to the file type that is in question. Then, reconfigure Outlook to block the file type by undoing the changes to the registry. For more information about how you can configure Outlook to block attachment file name extensions that Outlook does not block by default, click the following article number to view the article in the Microsoft Knowledge Base:
 

Method 2: Configure Outlook in an Exchange environment

If you run Outlook in an Exchange environment, the Exchange server administrator can change the default attachment security behavior. For more information about how to configure Outlook in an Exchange environment, click the following article numbers to view the articles in the Microsoft Knowledge Base: