Qmail content filter
 

Hello Guys,

I am looking to bounce emails to external domains from our domain, if the email body contains a certain combination of words (mainly to avoid leaking of one client information to the other).

My email server is qmail on CentOS5.

Can somebody suggest the right tool for this, if qmail does not provide this option already?

Please let me know if you need more information in this regard.

Thanks

Putting "linux qmail content filtering" into Google pulls up lots:

https://www.linuxquestions.org/quest...tering-866022/
http://www.fehcom.de/qmail/filter.html
http://www.chrishardie.com/qmail-anti-spam-howto/
http://qmail.org/top.html

Plenty of resources to get you started for content-filtering. Procmail is a very powerful tool, and all you're really looking for is a spam filter program. Set up the rules, and it's on the SEND portion of things, rather than on mail received. Also, you do realize what you're asking for is pointless, right?? If someone wants to get information off the premises, all they have to do is copy it to a CD, a USB drive, or attach an encrypted ZIP file to an outgoing message. Or even easier...just go to Gmail/Yahoo mail/whatever-mail from their web browser, and bypass EVERYTHING you put in place.

Thanks TBOne,

I shall look into those links you have given.

You are right. It is impossible to cover every possibilities. As I have mentioned in my original post, it is mainly to prevent accidental emails, from domain A, that may contain information (identified by combination of specific keywords) the should not go out of the domain. If the users knowingly decide to do this (by sending through a different mail server), it is unavoidable.

Thanks

You did not say in your original post it was to prevent 'accidental emails', but rather to prevent leaking client information in general. Since there is no way to prevent accidents, and you acknowledge that you can't avoid someone doing it on purpose, it seems like you're undertaking a good bit of work, and adding layers of complexity to your server (both for administration and maintenance), for no reason.

The choice is yours, of course, but I'd certainly not put time into this if it was me.

Thanks TBOne,

That's something to consider. I shall definitely take your advice. Thanks for that.