Custom File Extensions

File Extensions are helpful in identifying files contained in incoming email attachments. File extensions are used in File Rules which in turn are used in Spam/Virus/File Policies.  Utlimately Spam/Virus/File Policies are assigned to Internal Recipients in order to block or allow incoming email attachments on a per recipient basis. 

 Hermes SEG comes already pre-configured with dozens of file extensions but it's impossible for the existing File Extensions to encompass every possible file in existence. In this page, you can add or delete additional File Extensions as required. 

 Add Custom File Extension 

 

 In the  Add Custom File Entension  section, under the  Enter a File Extension in the box ....  field, enter the file extension you wish to add, ensuring you enter a ( . ) dot in front of the extension. For example, if you were adding the file extension for Microsoft Word document you would enter  .doc . 

 Under the  Select below whether you want the file extension to be case sensitive or case insensitive .... select either  Case Insensitive  or  Case Sensitive . It's recommended that you always select the Case Insensitive option unless you have a specific reason not to. 

 Under the  Select the type of File Extension you are adding in terms of risk...  select either  File Extension  or  High Risk File Extension . The High Risk File Extension option should be selected for File Extensions that are prone to carrying malware payloads. 

 Under the  Enter a description for your new File Extension...  enter a brief description. 

 Click the  Add  button ( Figure 1 ). 

 

 Figure 1 

 

 

 As you add Custom File Extensions, they will show up under the  Delete Custom File Extensions  section ( Figure 2 ). 

 

 Figure 2 

 

 Delete Custom File Extension 

 Note: If a file extension is part of a file rule, the system will NOT allow you to delete it. If that's the case, the file extension must first be removed from the file rule under Content Checks --> File Rules. 

 

 Under the  Delete Custom File Extensions  section, select the File Extension entry you wish to delete and click the  Delete  button ( Figure 3 ).  Note that only one entry can be selected at a time. 

 

 Figure 3