Mail.app's SPAM filter does NOT work correctly: check this out!
 

I have been in training mode for months but I can't seem to make the spam filtering in mail.app work correctly.
I get about 300 emails a day, of which about 270 are spam and about 100 get through the spam filter...
Today for example I got an email with subject "can't go to the beach?" and the content of the email was:

Stop wasting money on prescription drugs. Get them online for 80% off.
V1agra, C1alis, Xanax, Val1um, Xen1cal, And many many more...
Stop paying more than you have too!
Visit us here: http://onlineprescript.com/?refid=12

how can the filter possibly miss this? Are those number 1's all it takes to fool it? Or am I missing something?
Thanks

Did you happen to upgrade from Jaguar to Panther?

Yes I am 10.3.5, sorry for not mentioning. Mail.apps version is 1.3.9 (v619) and I didn't find info about newer versions... Tiger also doesn't seem to add much to Mail.app to look for.

But did you upgrade from Jaguar to Panther, or is Panther your first Mac OS?

I believe I had Panther when I bought the Mac. Why? What difference does it make?

There were some problems with the bayesian spam filter when one upgraded from Jaguar to Panther. If you've always been using Panther, then this problem should not effect you. However, I can assure you that the spam filter does work. I get about the same amount of traffic you do, with a similar amount of spam, and the filter catches about 99% of it.
Are you still in training mode?

Did you mean to write "should not affect you" or did you actually mean "should affect you" like you wrote?
I don't know what to do. Is there a way to fix this problem you are talking about? Patches?
I did a few months of training and then stopped being in training mode, even though I read somewhere that between training mode and "real" mode there is actually no difference between how Mail.app deals with spam.
What can I do?

Sorry, yes, should NOT effect you (corrected now).

nope, no Patches.


OK, if you're willing to experiment a little:
Make a back up of your Mail directory (~/Library/Mail/). The easiest way would be to make an archive of it. At least this way, no matter what happens, you can always fall back on this.

Move all your Junk mail, properly marks as spam or not to a "holding" mailbox, perhaps a new mailbox that you create. You want to make sure your Junk mailboxes are empty.

UNMARK it all, so it's NOT marked as spam.

Quit Mail.app.

Trash ~/Library/Mail/DefaultCounts & ~/Library/Mail/LSMMap2

Open Mail.app, but don't let it check mail.

Go to the Mail.app preferences and the Junk Mail tab. Click the "Reset" button (just in case), enable Junk Mail filtering, and put it in training mode.

Go to your junkmail "holding" folder and mark ALL those emails a junkmail.

Check your mail, and see if it does a little better job.

OR

You could just try and click the "Reset" button in the Mail.app/Junk Mail prefs, but in my past experiences, this didn't help the situation. For me (and others), the above files were corrupt.

I am willing to give this a try but I'll have to wait for some junk mail to pile up (matter of 3 or 4 days to have over 1000) because I usually delete them all and just did...
Thanks...
Is Apple aware of this situation? Is it a known bug?

It's not really a bug, per se. I'm thinking that the files that keep track of what should be marked as junk mail is corrupt.

In part, yes... I draw your attention to JunkMatcher. It adresses exactly this sort of issue. The project has evolved quite nicely since it was first hinted here. It is worth reading these pages for their insights into Mail's built in Junk routine if you are serious about building a set of custom rules. The Regexp link at the bottom of the page has proved useful. You can set this up as aggressive as you like by tinkering expressions or just by using the nifty interface that comes with. Updates to expressions are available.

Cheers to Ben.

What happens should I decide to pay $99/year for a mac.com address? How is junk mail filtered on their servers? Same as on Mail.app? Better? Worse?

As far as I can tell, there is no junk mail filtering on the server side of things with the Dot.Mac account. This is unfortunate IMO. Cox now has a wonderful filter that automatically disposes of all virus emails and optionally disposes or marks Junk Mail too!

What is Cox?

I have been going crazy lately looking for the best solution to fight spam that meets certain criterias I need (fyi: ability to fetch external pop3 accounts AND filter them / ability to create multiple personalities/signatures/from addresses on the webmail interface / ability to access email via imap/pop3/webmail and a few other requirements I had) so I have been testing lots of services... I wanted to mention them because, even though I am not writing reviews of them for me or other people, if somebody is going through the same thing I am we could exchange data and findings and I'd be happy to share my experience on the service providers I have tried out so far, which are:
Mailblocks.com
MacOsX.com
RunBox.com
Luxsci.net
and others...

Cox is my ISP. They've been very proactive lately to control Spam and Viruses. One drawback is that port 25 is blocked (Can't SMTP my own mail), but some sacrifices have to be made to get rid of the crap.

I followed your instructions but it didn't seem to have solved the issue unfortunately.

Sorry, I'm stumped. I can assure you that the spam filter works. Maybe you should call Apple at this point.

Let me add to that..

How much email/spam have you gotten since you started training it again?

Maybe...
well thanks for your help, I appreciate your time.

I downloaded JunkMatcher (thank you to who suggested it!) which seems a smart addition so maybe between that, the built in Mail.app junk filter and two server-side filter I'll get clean email...

Does somebody here know how to install Spam Assassin on webmail? I hear SA is good and that could be the solution, to install it on my own webmail so I don't have to pay for two ISPs' junk filters. I'd be willing to pay for the installation.

I suggested it. It would be trite to point out that squeaky clean email probably means missed mail. You are left with setting up your system depending on whether you deal better with false-negatives (missed spam) or false-positives (trapped legit mail) - I supect this is a personality dimension ;-} . Spammers are not stupid (just without ethics) - they change to combat anti spam methods so it is hard to guess what the next wrinkle will be.

Nobody so far has suggested a clean reload of Mail....

I thought about it but I don't know where to get the installation file of mail.app. Any ideas?

Off the installer DVD/CDs with Pacifist.

However, there's more to this then just replacing Mail.app. I'll let rgray give you the details.

I suspect this is work for something called Pacifist (can dig out .pkg) but, tho' I've read a little of it in these fora, I've not personally used it.

The big problem will be version... 10.3 -> 10.3.5 an I have not figured this... I personally favour a complete system reinstall.. When do we expect 10.4?