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Spam Filter

Vampy
Newbie
Posts: 8
Registered: 31-07-2007

Spam Filter

Hi

I have noticed that in the last few days more and more getting through the filters. Initially it got most of the rubbish,now its letting some of the viagra etc etc rubbish through.

I know its a complex issue, but it seems to be letting the obvious stuff through at times, where you would have thought that it would have not.

Comments?

Greig
11 REPLIES
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: 04-04-2007

Spam Filter

Hi,

I've noticed a few more spams recently, nothing really significant though. Problem with spam filtering is it's done on a number of factors rather than just subject or content and the spammers are always thinking up new ways of getting round filtering.

Best thing to do is forward the mails to the despam address, details here:

http://www.f9.net.uk/support/security/spam/spam_protection_guide.shtml?supportb=security_t5spam#5

and the spam filter will learn.
N/A

Spam Filter

I have got more spam from sites saying your family member has sent you an on-line card and go to get on their web page.

I fell for it the first time!!!

Could somebody tell me how to stop getting other pages popping up over the page your are viewing.

I have tried blocking pop ups block the web page address etc and still get them one was from saatchi and satchi who told me they don't have any pop up pages

Michael
N/A

Spam Filter

Quote
Best thing to do is forward the mails to the despam address, details here:

http://www.f9.net.uk/support/security/spam/spam_protection_guide.shtml?supportb=security_t5spam#5

and the spam filter will learn.


I keep sending the same spam to the address but they still keep appearing, how long does it take to train the filter.
Plusnet Help Team
Plusnet Help Team
Posts: 17,624
Thanks: 610
Fixes: 158
Registered: 05-04-2007

Spam Filter

Quote
how long does it take to train the filter.


Unfortunately there is no definitive answer to this, the training is done manually by someone going through the emails received to this address and using them to help train the filter.


Quote

I have tried blocking pop ups block the web page address etc and still get them one was from saatchi and satchi who told me they don't have any pop up pages


Have you made sure that your PC hasn't been infected with any spyware? Have a look at this guide for some tips.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Help Team
N/A

Spam Filter

I checked that my system is free from virus and spyware it only seems to happen on one web page for some reason

Unsure why

Michael
Moggy
Grafter
Posts: 99
Registered: 06-04-2007

Spam Filter

OK I'll say it and be made to look stupid, so the spam filter is a personHuh There's hope for the human race yet then!!!!
Moggy
Grafter
Posts: 99
Registered: 06-04-2007

Spam Filter

OK I'll say it and be made to look stupid, so the spam filter is a personHuh There's hope for the human race yet then!!!!
jmd
Grafter
Posts: 2,933
Thanks: 2
Registered: 30-07-2007

Spam Filter

I pity the person who acts as spam filter if they have to read all about the stuff I keep sending to spamfilter. There has been a increase though in last week of what has been getting through.
N/A

Spam Filter

I keep sending similar ones to the spam filter but they still keep coming through but if it is a person then they must be overloaded with work.
Mand
Grafter
Posts: 5,560
Thanks: 1
Registered: 05-04-2007

Spam Filter

Hi there,

The spam filter itself isn't a person, but we do check manually the email we actually use to train the filter to prevent mail incorrectly being marked and to ensure that the spam sent to the mailboxes is actually spam (and vice versa for the notspam address).

I understand the points being made, and I also recognise the fact that the spam filter isn't 100% successful.

The rest of this post is taken from Bob's lengthy explanation of the spam filtering elsewhere a couple of days ago:

Quote
DSpam (the system we use) can be used to train the spam engine but with it being a global thing the results aren't going to be as instant as we'd all like. The only way to really achieve near instant results with Bayesian filtering would be to have a classifier for each customer/each mailbox. This isn't something that's been ruled out but it would depend on a lot of people using Webmail or IMAP as opposed to POP3 (which the majority don't) and I doubt it would be too friendly on system capacity/CPU either.

With the global filter, the amount of email used to train the filter is also comparatively less than the overall volume of false positives/negatives that are forwarded to the despamchecker addresses. This means that only a representation of the forwarded emails are used each day. This is because they need vetting by a human before they are used.

We are investing a lot of resource into the mail API and spam controls in the aftermath of the webmail security incident. Results aren't going to be instant though as significant changes require a lot of planning, implementation and testing work to be done. We've often talked about outsourcing aspects of our spam filtering solution. To get something as reliable as say Googlemail requires a lot of resource, not least a dedicated team to adapt systems in line with the increasing and ever changing trends in unsolicited email. We've recently been trialling a solution provided by Critical Path across our internal email platform. It is picking up more than the customer facing systems but it will need refining and careful planning if and when it's rolled out to the customer base. Rest assured we are looking at alternatives and/or additions to DSpam.

Forwarding spam is best done by including a copy of the full email source complete with full headers. Our help article on the topic is here. This is quite easy to do in some mail clients like Thunderbird, but extremely cumbersome when using others like Outlook Express. Forwarding emails as attachments isn't much use when training the filter and it can be a pain to have to copy and paste headers into forwarded emails when using Outlook Express.

This is going to be made a lot easier for Webmail users soon as we'll be adding 'spam' and 'not spam' buttons to the webmail interface that do all the work for you.

We are rolling out some more improvements to the mail API soon that should help you combat the levels of spam you receive. The most notable of these is the functionality to turn off email sent to your virtual domain (the .plus.com address). What this allows you to do is register a free .co.uk domain, turn off the .f9.co.uk address and then use your new address with your existing mailboxes. Theoretically this should give you a spam free address however you would have to notify your contacts of the change.

The fact that common words are slipping through the filter is another commonly cited annoyance. In theory this could be addressed using content filtering but there are reasons why we have not chosen to do this. You would have to unpack every single mail to the disk, scan every line of text and check it for the words you're wanting to blacklist against. The email then needs altering for processing later on. If we had oodles of capacity then this might be worth considering but there's an awful lot of overhead for what you get and due to the changing nature of spam, a set of rules implemented today could well be rendered defunct in a few week's time.

We might look to see if we can implement a condition to reject email on the acl based on subject line. We could then populate a database to do this for some of the Wondercum emails and things like that.


I hope that this clarifies things for you a little as to what we are actually doing to resolve this issue. I'm hoping a lot of people will be able to dramatically reduce the volume of spam they're receiving by taking advantage of the new domain name and some of the added functionality that we'll be rolling out next week.
orrery
Grafter
Posts: 138
Thanks: 1
Registered: 30-07-2007

Spam Filter

Would F9/PlusNet not be better using a blocklist/blacklist based system, either instead of or in addition to filtering?

The system is remarkably effective on the Spamcop email system, as is their use of SpamAssassin with variable trigger levels.

regards, Ian