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Email filter not working!

Posted: Fri Feb 17, 2012 2:43 am
by Farid
I've been receiving spams for some time, and recently decided to use the filters in Exemail facility to stop them at the server level (i.e., deleting them from the inbox straightaway), but I still receive some of them on my Outlook and Entourage email applications! Can you please help me with this?
Regards,

Re: Email filter not working!

Posted: Fri Feb 17, 2012 9:28 am
by stevecJ
Farid wrote:I've been receiving spams for some time, and recently decided to use the filters in Exemail facility to stop them at the server level (i.e., deleting them from the inbox straightaway), but I still receive some of them on my Outlook and Entourage email applications! Can you please help me with this?
Regards,
Hi,

We cannot 100% grantee that all the spam emails will be blocked from the spam filter, as there are new spammers created every day.

When you receive new spam, you may forward them to 'spam@exetel.com.au' in order to train the spam filter.

Re: Email filter not working!

Posted: Wed Feb 29, 2012 3:44 am
by Farid
I've been doing this (forwarding the SAME spams) to the above email address (spam@exetel.com.au), and there has been no effect at all!! I really hope you can help me with this.

Re: Email filter not working!

Posted: Wed Feb 29, 2012 4:03 pm
by stevecJ
Farid wrote:I've been doing this (forwarding the SAME spams) to the above email address (spam@exetel.com.au), and there has been no effect at all!! I really hope you can help me with this.
Hi,

Sorry for the late reply, could you please forward some of the recent spam emails to 'hosting@exetel.com.au' in order to further investigate on this.

Re: Email filter not working!

Posted: Sat Mar 03, 2012 2:05 pm
by Farid
I've been forwarding the spam emails to the new email address [hosting@exetel.com.au], and still no avail! Surely there must be a solution on how to delete the spams at server level!?

Re: Email filter not working!

Posted: Mon Mar 05, 2012 11:04 am
by shoner
Farid wrote:I've been forwarding the spam emails to the new email address [hosting@exetel.com.au], and still no avail! Surely there must be a solution on how to delete the spams at server level!?
Thank you and we have received your email. As stated earlier, the spam filter is not 100% effective. You need to keep forwarding spam emails to 'spam@exetel.com.au' in order to train the spam filter.

Re: Email filter not working!

Posted: Mon Mar 05, 2012 11:57 am
by Dazzled
The Ironport filters are as good as you'll get. The main technique used in email filters depends on statistical probability as described by Bayes' Theorem. The filter needs to be "trained" to calculate probability. Spammers know that, and the intelligent ones keep trying to defeat the filter. Just retrain again, and their latest trick gets nullified. See http://en.wikipedia.org/wiki/Bayesian_spam_filtering.

A benefit of using an ISP filter common to many users rather than one just on your own machine is the variety and quantity of garbage that becomes useful training fodder.

Re: Email filter not working!

Posted: Tue Mar 06, 2012 10:59 am
by arachnologist
Dazzled wrote:The Ironport filters are as good as you'll get. The main technique used in email filters depends on statistical probability as described by Bayes' Theorem. The filter needs to be "trained" to calculate probability. Spammers know that, and the intelligent ones keep trying to defeat the filter. Just retrain again, and their latest trick gets nullified.
Ironport is not based on Bayesian filtering. Instead, IronPort AntiSpam uses SenderBase email reputation service with complicated system of white- and blacklists of IP addresses. So even the worst spam from whitelisted IPs goes through and most innocent emails originated from blacklisted IPs are filtered out.
http://www.senderbase.org

Re: Email filter not working!

Posted: Tue Mar 06, 2012 11:48 am
by Dazzled
Thanks for the info. My understanding was that Ironport was a mixture of IP reputation filters (Senderbase), and Bayesian statistical analysis of the text, as per http://www.clearview.co.uk/ironport_main.htm