Legit commercial emails gets eaten by spam filters (Anders Jacobsen's blog)

March 15, 2004

Legit commercial emails gets eaten by spam filters

I started thinking about some old discussions when I saw this piece:

Yahoo: Study: Spam Filters Often Lose E-Mails

A new study attempts to quantify missed bulk mailings. Return Path, a company that monitors e-mail performance for online marketers, found that nearly 19 percent of e-mail sent by its customers never reached the inboxes of intended recipients.

In some cases, the messages weren't delivered at all; in other cases, messages wound up in spam folders that are rarely checked. Though technical glitches can also cause mail to disappear, Return Path blames most of the deletions on spam filters.

Personally, I'm finding that the best indicator on whether inbound email is spam or not is whether it adheres to technical standards or not (does it have valid headers; is it sent through mailservers known to have sloppy enforcement of third-party email relaying? are the timestamps approximately accurate (mail from the "future" and "past" regularly arrive and is generally much more likely to be spam)...)

Content filtering seems to me to be less and less important in determining whether an email is spam - it might be a phase for spammers to clean up their act, but at the same time they need to keep breaking the RFCs to try to hide their puny identities.

I use Spam Assassin as my only tool at the moment, and I find that it (including its auto-learning Bayesian filtering) is reasonably accurate. I'm also considering Greylisting but I haven't gotten there yet...

Commercial newsletters I subscribe to usually get through my filter. If they are technically deviant (using odd HTML colours, containing HTML only etc) I can always whitelist the senders if I really want their mail to come through (but if they can't even bother sending technically correct/valid emails, I'm not always sure I can be bothered reading their messages...)

My 2 cents as usual...