up vote 0 down vote favorite
share [g+] share [fb]

We are using spamassassin to filter outbound mail generated from forms on web sites. I am not very satisfied with the amount of spam we are catching and so I am hoping to find a good application to help supplement it.

Since the forms are publicly accessible, the sender and recipient domains are subject to be anything. The IP address that the messages are sent from are our own web servers. So, DNS RBLs are of no value.

I am not opposed to buying a commercial product, but it would have to be one that is not licensed by number of mailboxes (since as I stated before the sender and/or recipient is subject to be anything).

Any recommendations on a good product?

link|improve this question
58% accept rate
Product and service recommendations are specifically off topic for ServerFault (see point 4 in the NOT About section of the FAQ) – sysadmin1138♦ Jan 5 at 3:19
feedback

closed as off topic by sysadmin1138♦ Jan 5 at 3:19

Questions on Server Fault are expected to generally relate to servers, networking, or desktop infrastructure, within the scope defined in the faq.

2 Answers

up vote 0 down vote

I'm amazed that forging From: addresses from your website hasn't gotten your domain on an RBL yet.

As for the question itself, adding captchas or limiting recipients may be your best bet.

link|improve this answer
Well this isn't "My web site". This is a shared hosted server with numerous customers on it. So they can have anything that they want (within legal limits of course). And "forged from:" addresses may trigger spam filters but surprisingly does not seem to mater to the RBLs. Even messages generated being sent with a yahoo or gmail FROM address deliver just fine to yahoo and gmail recipients. As for adding captchas, like I said, the sites aren't mine, they are customers so we have no control over the forms themselves. So all we can do is inspect the message body content as they are sent. – Alex Mar 23 '11 at 17:36
@Alex: Given those restrictions you are pretty well stuck being a spam source. You likely won't have enough content in the message to effectively filter spam. – BillThor Mar 23 '11 at 19:16
feedback
up vote 0 down vote

Put this on the webform:

<input type="text" name="comments" value="" id="comments_field" style="visibility:hidden"/>

And anything that fills it in is almost certainly a spambot.
Ref: Idea and theory shamelessly stolen from HTML Form Honeypot

link|improve this answer
feedback

Not the answer you're looking for? Browse other questions tagged or ask your own question.