AOL/Yahoo/GMail Spam Filters

There wasn’t much time for counting spam this week so I needed to do something simple. I forwarded my Pobox email email to 5 different addresses to compare the ISP spam filters. All these numbers are for the default filter settings without any additional training (if they support training) and received spam for 5 days.

Yahoo caught 119 spam messages and let 78 into my inbox for a 60% success rate.

GMail caught 194 spam messages and let 3 through for a 98% success rate.

Both Yahoo and Gmail received 197 spam messages over the 5 days. None of my AOL (“My eAddress”) accounts received anywhere near that number, even when spam filtering was turned off. This would indicate that AOL is doing their own filtering and stopping some email before it ever gets to the inbox. (Unless there were some delivery problems.)

The AOL mailbox with the spam filter set to low received 146 spam emails and let them all through to the inbox. Fifty one messages never made it to the mailbox.

The AOL mailbox with the spam filter set to medium stopped 36 and let 101 through to my inbox while 60 never made it to mailbox.

The AOL mailbox with the spam filter set to high stopped 47 while letting 88 through to the inbox. Sixty-two never made it to the mailbox.

I’ve been moving legitimate email off of the addresses that get my spam. So while there weren’t any false positives (or would that be false negatives?) the fact is I don’t get any legit email at those addresses anymore.

GMail is clearly better than the others at stopping spam. But the question that remains for me is whether it’s so aggressive it will stop legitimate email. Even with the AOL filter set to high it let through more spam than the Yahoo filter did. But but Yahoo and AOL let through so much spam I’d need a good email client to filter out what gets through. So, why have the email provider filter anything? If everything gets to the email client, and it has a good filter, there’s only one place to check for false positives.

I turned the Pobox spam filter back on and I’ll see how it does for the rest of the year.