Block emails containing URL's which link to .zip, .rar, .7z files

Created by Daniel Calkin, Modified on Wed, 29 Jan at 11:57 PM by Daniel Calkin

Some customers consider any URL's which are direct links to archive types of files to be too dangerous for their users to directly receive.  SpamSentinel can be configured to block most of these emails as Spam Category C by using the Regular Expression matching capabilities of the word blocking features that apply to HTML formatted emails.


See the end of this article for places you can get help understanding regular expressions if needed.


For each SpamSentinel Server Configuration document in the SpamSentinel Admin database the following changes need to be made:

 

1.  Check the box next to the option 'Inbound Word Lists' for the field 'Word Blocking' which is found on the White & Black Lists / Black Lists Tab.

 

 

 

2.  This check box will cause the field 'Inbound Words to Block' to become visible.

 

 

 

3.  Put the following regular expression into this list just as you see below enclosed in double square brackets:

 

[[(http|ftp|https)://([\w_-]+(?:\.[\w_-]+)+)(\/[\w_-]*)+(.zip|.rar|.7z)]]

 

 

4.  Emails with urls that end in .zip, .rar or .7z will now start getting blocked as Spam C with the blocking category designation of 'Word Block'

 

 

 

 

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Since regular expressions can be difficult to understand, here are some resources which might help make working with them easier.


1.  Quick Reference to Syntax (Note this is for JavaScript, but seems to work ok for .NET too)

 

 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Cheatsheet

 

2.  Testing and debugging with explanations of syntax

 

https://regex101.com/  NOTE: Choose 'ECMASCRIPT(JavaScript) in the left navigator.

   

 

 

 

3.  .NET Regex Tester (not sure if this perfectly matches what SpamSentinel is doing, but it was close enough for me to work with)

http://regexstorm.net/tester

 

 



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