Handling Attachments

Outlook 2003 handles attachments in much the same way as Outlook 2002. However, there have been a few minor changes in blocked file types.

Opening and Saving Attachments

There are several methods you can use to open or save an attached file. You can double-click the attachment's icon directly in the Reading Pane. Outlook will display Figure 19.18 asking you if you want to open or save the attached file.

Figure 19.18. Outlook warns you to open attachments only from sources you trust.

You can also right-click a message in the Inbox and select View Attachments to display a list of all available attachments. If you open a message, you can double-click the attachment's icon in the message header to open the attachment.

To save an attachment, select File, Save Attachments from the open email message. Select a location to save the attachment and rename the attachment if necessary. If a message has multiple attachments, you can save all of them to the same location using these steps. When saving multiple attachments at once with this method, you cannot rename the attachments. You can right-click the attachment's icon in the message header or in the Reading Pane and select Save As. Select a location for the file and click OK.

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You can open an attachment to an email and make changes to that attachment. In previous versions of Outlook, if you saved the attachment by clicking the Save button, that attachment wasn't necessarily saved. Outlook opens attached files in a temporary directory on your hard drive. When you exit Outlook, those temporary files are deleted. Outlook 2003 opens attachments in a read-only format. In order to save changes to the attachment, you'll have to save it to your hard drive in a new location.

Attachment Security

Soon after the Melissa and I Love You virus attacks were launched in 1999, Microsoft developed new security procedures for Outlook. There are two main components of these new security features: attachment blocking and an object model guard. If you receive an email with an attachment that's blocked by the new security features, you'll see a message in the InfoBar telling you the name of the blocked attachment, as shown in Figure 19.19.

Figure 19.19. Outlook blocks access to potentially harmful attachments.

One of the most frequently asked questions in the Microsoft newsgroups is, "How do I get access to my blocked attachments?" There are several ways you can access a blocked attachment. However, before you attempt to access the attachment, be sure that you have installed and properly configured antivirus software on your computer. Even if an attachment is from someone you know, there's no guarantee that it isn't infected with a virus. You could even receive an email from someone you know, with a file you are expecting, and it could be infected with a Word or Excel macro virus.

Virus protection is vital in this age of so much electronic communication. Consider how your business would suffer if all the files on your computer were suddenly gone. If you don't have a very recent backup, you could lose days, weeks, or months worth of work. Having an up-to-date antivirus product is the single best line of defense against viruses.

The other best practice to implement is never to open an attachment you aren't expecting without first contacting the person who sent it to you. Many of the viruses in the wild today will come from someone you know or appear to come from someone you know. Do not open a file simply because your mother sent it to you make sure that your mother did indeed send it to you before you proceed. If the file is safe, the sender likely won't mind you confirming that she did send you a file.

Outlook Attachment Blocking

By default, Outlook 2003 blocks 52 types of attachments. Table 19.1 lists the blocked attachment extensions and what they're used for.

Table 19.1. Blocked File Types in Outlook

File Extension	File Description
.ade	Microsoft Access project extension
.adp	Microsoft Access project
.app	Microsoft Visual FoxPro application
.asx	Windows Media Audio or Video Shortcut
.bas	Visual Basic class module
.bat	Batch file
.chm	Compiled HTML Help file
.cmd	Windows NT command script
.com	MS-DOS program
.cpl	Control Panel extension
.crt	Security certificate
.csh	KornShell script file
.exe	Executable program
.fxp	Microsoft Visual FoxPro compiled program
.hlp	Help file
.hta	HTML program
.inf	Setup information
.ins	Internet naming service
.isp	Internet communication settings
.js	JScript script file
.jse	.JScript-encoded script file
.ksh	KornShell script file
.lnk	Shortcut
.mda	Microsoft Access add-in program
.mdb	Microsoft Access database
.mdt	Microsoft Access workgroup information file
.mdw	Microsoft Access workgroup information file
.mde	Microsoft Access MDE database
.mdz	Microsoft Access wizard program
.msc	Microsoft Common Console document
.msi	Windows Installer package
.msp	Windows Installer patch
.mst	Visual Text source files
.ops	Office Profile settings
.pcd	PhotoCD image or Microsoft Visual Test compiled script
.pif	Shortcut to MS-DOS program
.prf	Microsoft Outlook profile settings
.prg	Microsoft Visual FoxPro program
.pst	Microsoft Outlook Personal Folders file
.reg	Registration entries
.scf	Windows Explorer command
.scr	Screen saver
.sct	Windows Script component
.shb	CorelShow presentation
.shs	Shell scrap object
.url	Internet shortcut
.vb	VBScript file
.vbe	VBScript-encoded script file
.vbs	VBScript file
.wsc	Windows script component
.wsf	Windows script file
.wsh	Windows Script host settings file

Microsoft identifies three different levels of attachments:

• Level 1 These attachments are completely blocked. All the attachments listed earlier are Level 1 attachments. You cannot save, delete, open, print, or otherwise access these attachments.

• Level 2 These attachments need to be saved to disk before they're opened.

• Level 3 These attachments can be opened directly from Outlook.

Accessing Blocked Attachments by Modifying the Registry

Outlook 2003 offers a method to access these blocked attachments. Through the use of a Registry key, you can downgrade an attachment's security level from Level 1 to Level 2. You cannot downgrade an attachment's security from Level 1 to Level 3 or from Level 2 to Level 3. Use the following steps to modify the registry to change file types from Level 1 to Level 2.

NOTE

Before modifying the Registry, make sure to back it up and have instructions handy for restoring the backed up Registry if a problem occurs. For more information on how to backup and restore the Registry, see Microsoft Knowledge Base article 256986, located at http://support.microsoft.com/?kbid=256986.

1. Quit Outlook 2003.

2. Click Start, and then Run.

3. Type regedit in the Run box and click OK.

4. Check to see whether the following Registry key exists:

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

   If so, skip to step 10.

5. If the key doesn't exist, create it. To create the Registry key, locate and select the following Registry key:

    HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook 

6. Click the Edit menu, New, and then Key.

7. Type Security and press Enter.

8. Select the Security key.

9. Click the Edit menu, click New, and then click String Value.

10. Type the following name for the new value:

     Level1Remove 

11. Click Enter.

12. Right-click the Level1Remove entry and click Modify.

13. Type the extensions of the file types that you want to move to Level 2. To type multiple extensions, use a semicolon as a separator value. For example:

     .exe;.bat 

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    You can type the extensions with or without the leading period.

14. Click OK.

15. Quit the Registry Editor.

16. Restart your computer.

When you restart Outlook, previously blocked extensions will be accessible. You'll need to save the Level 2 attachments to disk before you can open them. After you've created the Registry key, you can modify it at any time if you need to remove additional file types from the Level 1 list.

Do not remove all file types from the Level 1 list unless absolutely necessary. The list in Table 19.1 contains some files that are used frequently to transmit viruses. If you do not need to access these file types, leave them as Level 1 attachments.

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If modifying the Registry is a little too daunting, there's an add-in available from Outlook MVP Ken Slovak that will add a page to the Outlook Options dialog box to enable you to move attachments from Level 1 to Level 2. This add-in takes care of the Registry modification for you. For more information about this add-in, see www.slovaktech.com.

Other Methods of Accessing Blocked Attachments

There are three other methods available to enable you to view blocked attachments. If you're in an Exchange environment, your Exchange administrator can download and install an administrative security package that enables administrators to control access to attachments on a per-user or per-group basis.

For more information on configuring the Administrative Options package on the Exchange Server, see "Advanced Exchange Options," p. 683.

If your company offers Outlook Web Access (OWA) to Exchange Server, you can use OWA to access your blocked attachments. Because OWA doesn't filter any attachments, be sure that you have an antivirus product installed before you open any attachments from OWA.

The last method available for accessing attachments is an import to Outlook Express. Outlook Express blocks attachments by default; however, it also offers an easy method of turning its attachment blocking off.

To import a message with a blocked attachment into Outlook Express, use the following steps:

1. Create a new folder in Outlook and move any messages with blocked attachments into that folder. Creating this new folder enables you to import only messages you need into Outlook Express.

2. Open Outlook Express.

3. Select File, Import, Messages from the Outlook Express Import Wizard.

4. Select Microsoft Outlook as the import source.

5. Choose the folder created in step 1 and click Next to start the import.

6. Click Finish when the messages are done importing.

7. If you receive a message that Outlook Express blocked the attachment, select Tools, Options and click the Security tab.

8. Uncheck the box marked Do Not Allow Attachments to Be Saved or Opened That Could Potentially Be a Virus.

9. Click OK.

Although the preceding steps enable you to view attachments that Outlook 2003 blocks, there's one other way to ensure that you receive your attachments: Ask the sender to zip the files and resend them. However, depending on the sender, that's not always possible. If your boss is sending you an important file, she might not want to be bothered to resend the attachment. If you're corresponding with potential customers, you probably don't want to cause any additional hassle when you're trying to win their business. If they need to send you an Access database, it might just be easier to import the message into Outlook Express rather than bother your potential customer.