Gmail and the PBL

Yesterday I wrote about the underlying philosophy of spam filtering and how different places have different philosophies that drive their filtering decisions. That post was actually triggered by a blog post I read where the author was asking why Gmail was using the PBL but instead of rejecting mail from PBL listed hosts they instead accepted and bulkfoldered the mail.
The blog post ends with a question:

For those readers that know Gmail uses Spamhaus, I’d love to hear why Gmail couldn’t be transparent about its use.

I tried to post a comment, but it seems to have been eaten and never showed up on the post.
I don’t think this has anything to do with Gmail attempting to hide their use of outside blocklists. Rather, their technology is simply better suited to accepting and filtering after the SMTP transaction. Setting up a MTA to reject with different bounce codes for different reasons and notifying the sender of why can be a challenge for some.
Gmail’s philosophy is to accept all mail they can then filter it at the mailbox level. This philosophy drives both technology and system architecture. Trying to shoehorn in a different kind of filtering may be difficult or impossible without major changes. Then there’s the issue of maintaining a filter that is non-standard for the business. It makes perfect sense that Gmail sticks with their philosophy and filters mail from a PBL listed host.

Related Posts

Spam lawsuits: new and old

There’s been a bit of court activity related to spam that others have written about and I feel need a mention. I’ve not yet read the papers fully, but hope to get a chance to fully digest them over the weekend.
First is e360 v. Spamhaus. This is the case that actually prompted me to start this blog and my first blog post analyzed the 7th circuit court ruling sending the case back the lower court to determine actual damages. The lower court ruled this week, lowering the judgment to $27,002 against Spamhaus. The judge ruled that there was actual tortuous interference on the part of Spamhaus. In my naive reading of the law, this strikes me as not only an incorrect ruling, but one that ignores previous court decisions affirming that blocklists are protected under Section 230. Venkat seems to agree with me.

Read More

Legitimate mail in spamfilters

It can be difficult and frustrating for a sender to understand they whys and wherefores of spam filtering. Clearly the sender is not spamming, so why is their mail getting caught in spam filters?
I have a client that goes through this frustration on rare occasions. They send well crafted, fun, engaging content that their users really want. They have a solid reputation at the ISPs and their inbox stats are always above 98%. Very, very occasionally, though, they will see some filtering difficulties at Postini. It’s sad for all of us because Postini doesn’t tell us enough about what they’re doing to understand what my client is doing to trigger the filters. They get frustrated because they don’t know what’s going wrong; I get frustrated because I can’t really help them, and I’m sure their recipients are frustrated because they don’t get their wanted mail.
Why do a lot of filter vendors not communicate back to listees? Because not all senders are like my clients. Some senders send mail that recipients can take or leave. If the newsletter shows up in their inbox they may read it. If the ad gets in front of their face, they may click through. But, if the mail doesn’t show up, they don’t care. They certainly aren’t going to look for the mail in their bulk folder. Other senders send mail that users really don’t want. It is, flat out, spam.
The thing is, all these senders describe themselves as legitimate email marketers. They harvest addresses, they purchase lists, they send mail to spamtraps, and they still don’t describe themselves as spammers. Some of them have even ended up in court for violating various anti-spam laws and they still claim they’re not spammers.
Senders are competing with spammers for bandwidth and resources at the ISPs, they’re competing for postmaster attention at the ISPs and they’re competing for eyeballs in crowded inboxes.
It’s the sheer volume of spam and the crafty evilness of spammers that drives the constant change and improvement in spamfilters. It’s tough to keep up with the spamfilters because they’re trying to keep up with the spammers. And the spammers are continually looking for new ways to exploit recipients.
It can be a challenge to send relevant, engaging email while dealing with spamfilters and ISPs. But that’s what makes this job so much fun.

Read More

News and announcements: March 1, 2010

Some news stories and links today.
Spamhaus has announced their new domain block list (DBL). The DBL is a list of domains that have been found in spam.

Read More