McAfee Security for Microsoft Exchange 8.6.0

Configure file filtering rules

Create new rules to detect files based on their name, type, or size.

Before you begin

The file filtering rule triggers only when you select one condition. Make sure that you create an individual rule for each of these categories:

File name
File category
File size
This task provides information on configuring all three categories. Based on your Exchange organization's requirement, select only one category for a file filtering rule and create separate rules for each category. If a rule contains multiple criteria such as File name filtering, File category filtering, and File size filtering, all criteria must be satisfied to trigger the rule.
Task
1 From the product's user interface, click Policy Manager | Shared Resource.
2 Click DLP and Compliance Dictionaries tab.
3 From File Filtering Rules, click Create New.
4 Type a unique Rule name. Give the rule a meaningful name, so that you can easily identify it and what it does. For example, FilesOver5MB or Block MPP files.
5 Enable Evaluate items inside archive files.
Select this option, if the File Filter rule is applicable for scanning archive files. By selecting this rule, the subsequent File Filter rules are applied on archive files.
6 In the File Filtering Rule page, you can use:
Option definitions — filename filtering
Option Definition
Enable file name filtering To enable file filtering according to the file names.
Take action when the file name matches Specify the name of the files that triggers this rule. You can use wildcard characters (* or ?) to match multiple file names. For example, if you want to filter any Microsoft PowerPoint files, type *.ppt.
Add To add the file name specified under Take action when the file name matches, to the file name filtering list.
Edit To edit or modify an existing file filtering rule.
Delete To remove the file name from the filter list.
You cannot delete a file filtering rule, if it is used by any policy. The Used By column must display 0 policies for the rule that you want to delete. You must first remove the file filtering rule from the policy, then click Delete.
Option definitions — File category filtering
Option Definition
Enable file category filtering To enable file filtering according to their file type.
Take action when the file category is Specify the type of files that affects this rule.
File types are divided into categories and subcategories.
File categories Select a file type category. An asterisk symbol (*) appears next to the file type, to indicate that the selected file type will be filtered.
Subcategories Select the subcategory you want to filter.

To select more than one subcategory, use Ctrl+Click or Shift+Click.

To select all of the subcategories, click All.

Click Clear selections to undo the last selection.

Extend this rule to unrecognized file categories To apply this rule to any other file categories and subcategories that are not mentioned in the categories and subcategories list.
To allow through the password-protected .zip files that contains restricted files, make sure that the Password protected bypass rule appears as a first rule in the list.
Option definitions — File size filtering
Option Definition
Enable file size filtering To filter files according to their file size.
Take action when the file size is Specify a value in the adjacent text box and drop-down list, then select:
Greater than — To specify that the action should only be applied if the file is larger than the size specified.
Less than — To specify that the action should only be applied if the file is smaller than the size specified.
7 Click Save to return to the Shared Resources page.
8 Click Apply to create the file filtering rule.
You have now successfully created a file filtering rule, to suit your Exchange organization's requirement.