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Webased email anti-spam

Hi,

I have several people that check their email accounts online via the web. I have this http://omusicstudios.com/webmail hosted on bluehost.com. It's automatically created and have different options of GUI email functionality between Horde and others.

The workers are complaining about spam. I know bluehost has their google postini anti-spam but I don't wish to pay for it. I was thinking that perhaps I can route my email through some intermediary email servers (Centos Linux) that I can set up from the office which will have something like SpamAssassin on it. I was thinking I can route these emails through this filtering process and then forward to the appropriate email accounts.

Is this even possible? If so, where would I start? I can set up the email servers on a Centos system.

Any help or suggestions is appreciated. =)

Thanks,
Victor
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interesting question..to be honest paying for good antispam I find easier to justify than paying for antivirus as there are several good free av products.
there are "cloud" based aspam services that will route the mail through them and then on to the original mail host - but there is a charge.
for the effort you will go to and then your costs you may well find that your clients wont mind paying the comparitively small fee for antispam.
you may also find it worthwhile to look at hosting their mail yourself,
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Commented:
I understand that you're trying to do it for free, but even though SpamAssassin is pretty good, it's nowhere near the leve of Postini. Plus, you'll have to be pretty good at coding to create SpamAssassin HAM and SPAM training filters.

Having said that, if you still want to do it that way, you don't need to "forward" the mail anywhere and then "forward" it back. You can just change the MX records for your domain to a new mail server that supports SpamAssassin. You can then change the DNS records so that http://omusicstudios.com/webmail points to the new webmail server.
Victor KimuraSEO, Web Developer

Author

Commented:
Hi wolfcamel,

How much would it cost my clients? What are some good cloud based services that are inexpensive. We have around 20 to 25 emails for this one company.

I also have other clients with similar problems who use Outlook and lots of spam. Yes, I have a VPS so I was thinking of hosting the mail on the VPS.

So SpamAssassin is not as good as Postini. I can't compare to Google for certain. But I was thinking of mitigating the problem to a degree that is acceptable I guess. I think using Postini for one client with 20 to 25 emails mostly using IMAP can be costly.

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Hi btdownloads7,

I'll look at SpamAssassin HAM and SPAM training filters. I thought SpamAssassin had some Bayesian filters which train the filters though.

Is there something better or some additional "plug-in" that I can use in addition to SpamAssassin to reduce the level of spam on a Linux system or some professional grade system perhaps that doesn't cost an arm and a leg?

I'm trying to see some open-sourced solutions that are viable and that are good.

Thanks,
Victor
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Commented:
The bayesian filters just have a spam level rating that you can adjust. To really get it working well (just like most spam filters), you have to tell it when it does something wrong. So, each user willl get a HAM and SPAM folder in their inbox, and whenever they see a spam message that got through, they will need to put it in the spam folder. And if they see a good message that got put into spam, the'll need to move it into the ham folder. The script that you have to set up then goes through each user's ham and spam folders and basically reports to SpamAssasin what was done wrong. And over time, that improves its bayesian filters.

As far as cloud services go, your best and cheapest bet is Google business Gmaill (http://www.google.com/apps/intl/en/business/gmail.html). It's pretty inexpensive at $50 per user per year, and they basically host your domain's email, but itnlooks and works like normal Gmail. They also let you use Postini for free if you prefer that to Gmail's native spam filters.
Victor KimuraSEO, Web Developer

Author

Commented:
Hi btdownloads7,

Re. the bayesian filters. I head that Thunderbird (though a client program) uses SpamAssassin and it uses the bayesian filters when one sets the emails as either junk or not junk. I heard it learns it over time.

Google is expensive. One of my clients have 2o to 25 email accounts. I have other clients with 5 to 10. I think the solution would be for me to use a VPS and email server. I think that seems to be the best option.

You mention about coding SpamAssassin for HAM and SPAM filters. Any links that I can learn from? Any other server-side programs that I can use for Linux (open-sourced preferably) and ones that are reputable.

Thanks,
Victor
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Commented:
Let's clarify something (because you're mixing up spam filters) -- SpamAssassin does Bayesian spam filtering on the server end, and Thunderbird does completely different spam filtering on the client end. When SpamAssassin is done processing a message, it attaches an X-SPAM header with a numerical spam score. That's what TB checks for when you say that it "uses" SpamAssassin. It doesn't really matter how TB "learns" because its just following SpamAssassin's scores.

Here's a basic explanation of how the HAM and SPAM training is supposed to work: http://wiki.apache.org/spamassassin/BayesInSpamAssassin, but there are a lot of more detailed tutorials if you need them
symantec have a hosted spam solution - you pay per domain, not per mailbox (from memory) and not sure about pricing.
Victor KimuraSEO, Web Developer

Author

Commented:
Thank you. Will look into Norton hosted spam.

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