The update is available through Thunderbird’s auto update feature. Both the OS X and Windows versions required Thunderbird to be restarted after the update.

The full version for Windows, OS X or Linux for all supported languages (included the just added Korean version) can be downloaded from Mozilla.

The setup had the spam filter off at my email forwarder with email forwarded to both my Yahoo account and my .Mac account. The spam filter at Yahoo was off so all mail passed through to my Thunderbird client. The .Mac filter isn’t configurable by me so it would stop some email. Both services would receive the same email as both these services only receive email via my forwarder. I don’t give out the direct addresses for either. And much to much surprise and delight neither is attracting spam on it’s own.

During six days last week 324 emails passed through the system. This 324 number is the actual spam messages and does not include false positives marked as spam and it does not include non-spam.

.Mac/Apple Mail

While Apple Mail is not limited to .Mac I treated it as a single system for this week. To keep things consistent I only used mail from .Mac to train the junk mail filter in Apple Mail and these numbers are only for the email sent to .Mac. Of the 324 spam emails only 113 were actually delivered to my mailbox, the rest were stopped by the .Mac filters. Here’s an article (apple.com) that discusses Apple’s use of Brightmail and it’s other spam filtering techniques. The downside to having .Mac block email is that some email was blocked and I’d have no way of knowing it if it was only sent to my .Mac mailbox. These were all bulk emails and so far adding the sender to my address book has allowed future emails through. Of the 113 spam emails 108 of them were flagged as junk by Apple Mail. Five emails were missed. Apple mail had 8 false positives. Again, these 8 were all bulk emails. The percentage of missed and false positives did go down as the week progressed (as previous errors were marked and the filter was trained). But the amount of email is too small and the time frame too short to know whether this is due to improvements in the filter or just coincidence. So the bottom line for a .Mac/Apple mail combo: Spam Filtered: 319 [98.5%] (211 by .Mac and 108 by Apple Mail) Missed: 5 emails [1.5%] False Positives: 11 [3.4%] (3 blocked by .Mac and 8 by Apple Mail)

Thunderbird (Mac) Thunderbird was used for delivery of the email sent to my Yahoo account. Since I turned off the Yahoo spam filter all 324 emails came to my PC. Thunderbird flagged 291 as junk, missed 33 and had 6 false positives. For filter training all email was marked as “spam” or “not spam” each day. What’s interesting here is that the junk filter did not seem to improve as the week went on. In fact, on the last day it caught 13 but missed 15 (which was also the day that had the fewest spam messages). The day seems to be a anomaly and accounted for almost half the missed messages for the week. The bottom line for Thunderbird: Spam Filtered: 291 [89.8%] Missed: 33 emails [10.2%] False Positives: 6 [1.9%]

Spam Destinations

As I mentioned in my previous post I’ve been looking at which of my email addresses get the spam. The previous trend continues. The address I give to real people but have never personally used on a website or mailing list gets 45% of my spam. My tier 3 “I expect you to spam me” address does get 50% of my spam but on 3 out of 6 days I received more spam on my “people only” address than I did on this one.

Other Numbers

My GMail account received 21 spam messages over the week and caught all of it. There weren’t any false positives. The time period isn’t the same as the other numbers but AOL stopped 87 spam messages and let 160 through.

Conclusions and Next Week

First the disclaimer: This is only a small sample over a short period of time using a small specific sample so these conclusions won’t apply to everyone. Apple Mail has been my primary email client for awhile but I’ve always had my ISP spam filters turned on. I’m pleasantly surprised it’s doing so well especially when compared to Thunderbird. It’s time to move to the next step. Apple Mail and Thunderbird will both process email from Yahoo and we’ll see how they compare after a week of processing the same email. EMail isn’t deleted from the server so the same messages will be delivered to both clients. .Mac/Apple Mail is a good choice from the perspective of the amount of spam blocked. The fact that I can’t see what email it blocks is a problem for me. Sometimes the sender address isn’t obvious (when I register my email address) and if the email is never seen the sender can’t be added to my address book. Plus, if I don’t see it I can’t count it! .Mac alone (using only the web) wouldn’t be a good choice for me. To much spam gets through .Mac’s own filters and there’s no way to tweak it on the web which makes it tedious to manage mail via the web interface. (I do have a general bias against most email web interfaces.) I’ll be dropping .Mac from my testing, at least in the near future. Because the AOL web software crashes both Firefox and Safari on my Mac I haven’t been able to consistently manage/mark spam it receives so it shouldn’t be directly compared to the other services. So next week I’ll be working on direct comparisons between Apple Mail and Thunderbird (Mac). I’m going to also try setting up some better testing of the AOL spam capabilities.

The only two places spam arrives directly from the internet are at my email forwarder and GMail.

GMail
Gmail (Google Mail) received 18 Spam e-mails over 5 days. There were not any false positives and no spam got through.

Pobox – Mail Forwarder
My mail forwarding service, pobox.com, flagged and held 339 emails as spam over a 5 day period. The only false positives were from one sender. It was an bulk advertising e-mail, but from a place I’d done business with. I could have added the sender to the whitelist, but I chose to unsubscribe instead.

As has been mentioned, ISPs handle email differently when it’s from a forwarder than they do when it’s direct. The three accounts the mail is being forwarded to only receive email from the forwarder. (The .Mac account gets a few e-mails from Apple and the Yahoo account gets a few e-mails from Yahoo.) If my email forwarder didn’t detect a message as spam it passed it along. I had the e-mails sent to my Yahoo, .Mac and AOL (“My eAddress”) accounts.

Yahoo
I reset the junk filter when I started. As I checked the mail each day I used Yahoo’s junk mail button to properly mark the e-mail and train the filter. Only e-mail not caught by the forwarder was sent to Yahoo.

The first day Yahoo missed 10 out of 11 junk e-mails. But even with just these e-mails as training it started catching more than it missed from that point on. During the 5 day period Yahoo caught 19 junk emails and let 17 through.

There was one false positive which was a marketing e-mail which I added to my address book for future delivery.

There was another marketing email where the exact same email was sent to two of my email addresses. Yahoo saw one as junk but not the other. I’m guessing it was the second one that if flagged as junk rather than an inconsistency.

.MAC Mail
.Mac mail does not have any web based spam filter, at least not visible to the user.Typically, only 1/2 the junk email appeared in my mailbox. One of the undelivered emails was a daily report I receive. I added the sender address to my address book on my Mac. From that point on these emails were received. I do sync my address book with .Mac.

AOL (My eAddress)
Over the 5 day period AOL flagged 21 emails as junk and let 31 go through. The first day is the only time it caught more than it let through. It performed worse as it was trained. There weren’t any false positives. AOL seems to be applying its own filter before delivering the mail as the number of emails received in my AOL box was less than the number delivered to Yahoo.

Apple Mail
I used Apple mail to read mail delivered to my .Mac account. The first day Apple Mail caught 10 and missed 10 junk mails. After that initial training it improved dramatically catching 6 and missing 1.

Apple mail also flagged 5 emails as junk which were not. Not all of these were bulk emails. Two were transaction receipts or info requests sent directly to me. But it’s almost a given that they were sent using an automated system that handles a large volume.

As a test, after delivery of the mail from .Mac mail I downloaded mail from Yahoo. This would duplicate the mail received from .Mac mail. Mail that had been marked as junk or not junk when received from .Mac mail was properly processed.

Thunderbird
Thunderbird had the slowest junk mail filter to train. It also requires marking both junk and non-junk mail to train it. As a small, unscientific test I tried just marking junk for the firs couple of days. The filter made no real improvement despite a large volume of junk. I reset the filter and started marking every email received as either junk or not junk. There was a noticeable improvement right away. The first two days it missed everything, the last two days it caught everything. Thunderbird had 1 false positive which was a bulk email, the same sender that I had to add to my Yahoo address book to let through. For Thunderbird I marked it not junk and added the sender to my “Collected Addresses”.

Thunderbird on Windows handled the junk email the same way it did on Mac. I used the same emails for training.

Outlook Express
I looked at Outlook Express on Windows XP SP2. The only junk mail tool is a blocked address list.

Next Week
Ideally what I want is for all mail to be delivered to my desktop inbox and let it filter for junk mail. This keeps me from having to go to another location to look for blocked email that I actually need.

I turned off the spam filters at my email forwarder and at Yahoo. This week we’ll see how well Thunderbird and Apple Mail handle the spam.

• None of the e-mail was sent to the Yahoo mail account directly. I have never given out this address to anyone and was happy to see there wasn’t any spam for it in this bunch.
• Two of the spam e-mails came from the address I use on shopping sites. One was from a motor club I had given the address to. But it was a sales pitch. Also, Thunderbird flagged it as a potential e-mail scam. It contained unsubscribe info which I followed. The other e-mail was pure spam.
• 37 of the e-mails were sent to an address I had since 1998 and I no use whenever I suspect it may be grabbed for spam.
• 22 of the spam e-mails were sent to an address I use for family and friends and other real people. I personally don’t use it on web sites but I know it has been used at greeting card and similar sites.

One quick comment about unsubscribing from e-mail lists. I typically don’t, for fear of confirming it’s an active e-mail or visiting a hostile website. But in this case the e-mail was sent from what should be reputable organization. Also, it was sent to an e-mail address I’m moving off of and can delete when my spam research is done. It’ll be interesting to see how the unsubscribes go.