The element contains potentially unsafe attachments how to remove. Outlook attachment blocking: what is the problem and how to deal with it

30.04.2021

Unblock!

If you are not using Outlook with Exchange, or if your Exchange administrator allows users to change the Outlook Attachment Security Mode, use Method 1: Configure Attachment Security Mode.

If Outlook is used with an Exchange server and the Exchange Server Administrator has disabled changes to Outlook Attachment Security, use Method 2: "Configure Outlook in an Exchange Environment."

Method 1: Configure Attachment Security Mode

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems can occur if you modify the registry incorrectly. Therefore, be sure to follow the steps below. For added protection, back up the registry before making changes. Then, if a problem occurs, you can restore the registry. 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 configuring attachment security in Outlook 2000 SR1 and Microsoft Outlook 2000 SR1a, you must apply Microsoft Office 2000 Service Pack 2 or Microsoft Office 2000 Service Pack 3.

Follow these steps to modify the registry and change the attachment security mode in Outlook.

Close Outlook if it is running.

On the menu Start select team Execute... Copy and paste (or type) the following command in the window Open and press Enter:
regedit

Make sure the following registry key exists for your version of Outlook.
Microsoft Office Outlook 2010
HKEY_CURRENT_USER \ Software \ Microsoft \ Off ice \ 14.0 \ Outlook \ Security
Microsoft Office Outlook 2007
HKEY_CURRENT_USER \ Software \ Microsoft \ Off ice \ 12.0 \ Outlook \ Security
Microsoft Office Outlook 2003
HKEY_CURRENT_USER \ Software \ Microsoft \ Off ice \ 11.0 \ Outlook \ Security
Microsoft Outlook 2002
HKEY_CURRENT_USER \ Software \ Microsoft \ Off ice \ 10.0 \ Outlook \ Security
Microsoft Outlook 2000
HKEY_CURRENT_USER \ Software \ Microsoft \ Off ice \ 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. Find and highlight the following registry key:
  HKEY_CURRENT_USER \ Software \ Microsoft
2. In chapter The change press the button Create and choose chapter.
3. Type Office, and then press Enter.
4. In chapter The change press the button Create and choose chapter.
5. Open Outlook 2010, type 14.0, and then press Enter.
  For Outlook 2007, type 12.0, and then press ENTER.
  Outlook 2003 type 11.0 and then press Enter.
  For Microsoft Outlook 2002, type 10.0, and then press Enter.
  Outlook 2000 type 9.0 and then press Enter.
6. In chapter The change press the button Create and choose chapter.
7. Type Outlook and then press Enter.
8. In chapter The change press the button Create and choose chapter.
9. Type Security, and then press Enter.

In chapter The change press the button Create and then String parameter.

Copy and paste (or type) the following name for the new parameter:
Level1Remove

Press Enter.

Right-click the name of the new parameter and click Change.

Enter the file name extension, the type of file you want to open in Outlook. For example:
To specify multiple file types, use the following format:
Exe; .COM

Click the button OK.

Close Registry Editor.

Reboot your computer.

When you start Microsoft Outlook, you can open files of the types specified in the registry.

Note Microsoft recommends that you enable the file types you must have. If a particular file type is rarely used, Microsoft recommends that you give Outlook temporary access to the file type in question. Configure Outlook to block this file type by returning the registry. For more information about how to configure Outlook to block the file name extension that Outlook does not block by default, click the following article number to view the article in the Microsoft Knowledge Base:

Method 2: Configuring Outlook in an Exchange Environment

When using Outlook in an Exchange environment, the Exchange server administrator can change the default attachment security mode. For more information about customizing Outlook in an Exchange environment, click the following article numbers in the Microsoft Knowledge Base:

15.06.2017

The protection system integrated into the MS Outlook software product does not allow the user to accept files of certain formats, for example, files with the .exe extension to prevent malware from damaging your PC.

In the initial setting of Outlook, files with certain extensions are blocked. In addition, a number of recent updates for Microsoft Outlook, including KB3191932, KB3191938 and KB3191898, are capable of blocking user interaction with attachments.

Ways to solve problems with attachment blocking

To solve such a problem, some have resorted to the following solutions:

compression of sent attachments, for example programs with a certain extension and nodes in the archive;
renaming the file format to an undetectable format by MS Outlook - in this case, Outlook will not block the file without recognizing it. After receiving the file, you can reassign it to the original extension.

The method of reconfiguring the security mode also helps to cope with the problem. In this case, the user will need to make certain changes to the registry (a preliminary backup copy of the registry data is required). To make changes to the registry, use the regedit command and make sure that the following sections are in the registry:

For Microsoft Office Outlook 2003

HKEY_CURRENT_USER \ Software \ Microsoft \ Office \ 11.0 \ Outlook \ Security

For Microsoft Office Outlook 2007

HKEY_CURRENT_USER \ Software \ Microsoft \ Office \ 12.0 \ Outlook \ Security

For Microsoft Office Outlook 2010

HKEY_CURRENT_USER \ Software \ Microsoft \ Office \ 14.0 \ Outlook \ Security

If you do not find the registry key specified for your version of MS Outlook, you will have to create it. Find and select HKEY_CURRENT_USER \ Software \ Microsoft... In the parameter "Change" push "Create" and choose "chapter"... Next, enter the name Office and click "Enter"... Through the command "Change" select the item again "Create" and select the section.

For Outlook 2010, enter 14.0;
For Outlook 2007, enter 12.0;
For Outlook 2003, we specify 11.0.

Further, according to the same scheme, we create a new section in the registry. "Security" and a security settings string parameter with the value Level1Remove... Now RMB on the name of the newly created parameter and then "Change"... Enter the extension of the file type that you want to be allowed to open in Outlook attachments. To specify several allowed file types in attachments, we write them, separating them with a semicolon.

E-mail is still one of the main sources of delivery of viruses and trojans to computers of end "consumers". To protect users of its mail client from viruses that spread in this way, Microsoft, starting with Outlook 2000, introduced a mechanism for blocking unsafe attachments in Outlook. Blocking unsafe attachments is the inability to open potentially dangerous files received as email attachments in Outlook.

Outlook attachment classification

There are 3 different security groups that are used to classify attachments in Outlook:

Level 1- unsafe attachments
Level 2- medium-risk files-attachments that cannot be opened directly from Outlook (to open an attachment, you must first save it to disk)
Level 3- other attachments that can be opened directly in Outlook

Level 1 includes the following file types that are blocked from opening in Outlook:

* .ade, * .adp, * .app, * .asp, * .bas, * .bat, * .cer, * .chm, * .cmd, * .cnt, * .com, * .cpl, *. crt, * .csh, * .der, * .exe, * .fxp, * .gadget, * .hlp, * .hpj, * .hta, * .inf, * .ins, * .isp, * .its, * .js, * .jse, * .ksh, * .lnk, * .mad, * .maf, * .mag, * .mam, * .maq, * .mar, * .mas, * .mat, *. mau, * .mav, * .maw, * .mda, * .mdb, * .mde, * .mdt, * .mdw, * .mdz, * .msc, * .msh, * .msh1, * .msh2, * .mshxml, * .msh1xml, * .msh2xml, * .msi, * .msp, * .mst, * .ops, * .osd, * .pcd, * .pif, * .plg, * .prf, *. prg, * .pst, * .reg, * .scf, * .scr, * .sct, * .shb, * .shs, * .ps1, * .ps1xml, * .ps2, * .ps2xml, * .psc1, * .psc2, * .tmp, * .url, * .vb, * .vbe, * .vbp, * .vbs, * .vsmacros, * .vsw, * .ws, * .wsc, * .wsf, *. wsh, * .xnk

Level 2 does not include any file type by default. Specific file types can be included in this group only after manual configuration by an administrator on a Microsoft Exchange Server (of course, if Outlook uses a mailbox on such a mail server).

For example, in Outlook, a letter with a reg file attached (we sent a reg file with new time zone settings for Windows XP), the following message appears in the information line:

Outlook blocked access to the following potentially unsafe attachments: TZ_WindowsXP.reg

In the Russian version of Outlook, the error looks like this:

Outlook has blocked access to the following unsafe attachments.

The most interesting thing is that the Outlook interface basically lacks the ability to open or view a blocked attachment. Typically, users familiar with this Outlook behavior simply ask the sender to resend the file, renaming its extension to something more secure, or zipping it, for example, into a zip or rar archive.

In general, this behavior of Outlook is justified and quite effectively prevents users from launching unsafe files. However, in some environments, this protection is unacceptable (for example, for technical support services or software developers). Next, we will show how you can unblock and save the received attachment in Outlook with the help of a small registry modification.

Important... Let us remind you once again that the procedure for blocking "dangerous" file types in Outlook is vital element in computer security... If you disable this mechanism, the security of your computer is at risk. Do not forget that in no case should you open / run files received from unknown senders, and all received files should be scanned using the latest anti-virus databases. In most cases, it is preferable to receive the file in a more secure way, for example by requesting it again from the sender in an archived form. After saving the required attachment, it is strongly recommended to return the changed registry parameters to their initial state.

Change registry settings to block unsafe Outlook attachments

Close Outlook
Launch Registry Editor and go to branch HKEY_CURRENT_USER -> Software-> Microsoft-> Office-> (Code of your Outlook version) -> Outlook-> Security

Note... Each Outlook version has its own (internal) version number, the table below shows the correspondence

E-mail is still one of the main sources of delivery of viruses and trojans to computers of end "consumers". To protect users of its mail client from viruses that spread in this way, Microsoft, starting with Outlook 2000, introduced a mechanism blocking unsafe attachments... Blocking unsafe attachments is the inability to open potentially dangerous files received as email attachments in Outlook.

There are 3 different security groups that are used to classify attachments in Outlook:

Level 1- unsafe attachments
Level 2- medium-risk files-attachments that cannot be opened directly from Outlook (to open an attachment, you must first save it to disk)
Level 3- other attachments that can be opened directly in Outlook

Level 1 includes the following file types that are blocked from opening in Outlook:

Level 2 does not include any file type by default. Specific file types can be included in this group only after manual configuration by the administrator on the server (of course, if Outlook uses a mailbox on such a mail server).

For example, in Outlook a letter with an attached reg file (we sent a reg file with new settings), an inscription appears in the information line:

Outlook blocked access to the following potentially unsafe attachments: TZ_WindowsXP.reg

In the Russian version of Outlook, the error looks like this:

Outlook has blocked access to the following unsafe attachments.

To get Outlook to block the specified attachments again, simply remove the Level1Remove parameter in the registry.

When you receive a message with an attachment in Microsoft Outlook, the following may appear above it or in the Reading Pane:

Outlook has blocked access to the following potentially unsafe attachments:

All versions of Outlook, starting with Outlook 2000 Service Pack 1 (SR1), have a security feature that blocks access to attachments that might contain viruses or other threats. Although access to attachments is blocked, they are still contained in the message.

Additional Information

Important! This section, method, or task description includes information about modifying registry settings. However, changing them incorrectly can cause serious problems, so be sure to follow the instructions carefully when performing these steps. For additional protection, back up your registry. In this case, if a problem occurs, the registry can be restored. For more information about backing up and restoring the registry, see the following article in the Microsoft Knowledge Base:

Attention! Microsoft Office 2000 Service Pack 2 (SP2) or SP3 must be installed prior to configuring attachment security settings in Microsoft Outlook 2000 with Patch 1 (SR1) or 1a (SR1a).

To change the attachment security settings for Outlook in the registry, follow these steps:

Close Outlook if it is running.
On the menu Start select item Execute... Copy and paste or type in the field Open the following command and press ENTER:
regedit
Check if the following registry key exists (the name of the key depends on the version of Outlook you are using).
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, create it. To do this, follow the steps below.
1. Find and open the following registry key:
  HKEY_CURRENT_USER \ Software \ Microsoft
2. On the menu Edit select team Create and then item Chapter.
3. Type Office and press Enter.
4. On the menu Edit select team Create and then item Chapter.
5. For Outlook 2010, enter 14.0 and press Enter.
  For Outlook 2007, type 12.0 and press Enter.
  For Outlook 2003, type 11.0 and press Enter.
  For Outlook 2002, type 10.0 and press Enter.
  For Outlook 2000, enter 9.0 and press Enter.
6. On the menu Edit select team Create and then item Chapter.
7. Type Outlook and press Enter.
8. On the menu Edit select team Create and then item Chapter.
9. Type Security and press Enter.
On the menu Edit select team Create and then item String parameter.
Copy and paste or enter the following name:
Level1Remove
Press Enter.
Right-click the name of the new parameter and select the command Change.
Enter the file extension of the type you want to open in Outlook. For example:
To specify multiple file types, use the following format:
Exe; .com
Click the button OK.
Close Registry Editor.
Reboot your computer.

After starting Microsoft Outlook, you can open files of the types specified in the registry.

Note... We recommend that you perform this operation only for the required file types. For file types that are rarely used, it is recommended to grant temporary access. To block file types in Outlook again, undo the changes to the registry settings.