Another Case Against Blacklists

This was just too good to pass up.  Our customer support person just received this bounce and sent it to me for diagnostics:

From: MAILER-DAEMON@mail01h.rapidsite.net

Date: 4 Mar 2005 03:57:51 -0000

To: yyy@zzz.com
Subject: failure notice

Hi. This is the qmail-send program at mail01h.rapidsite.net.

I'm afraid I wasn't able to deliver your message to the following addresses.

This is a permanent error; I've given up. Sorry it didn't work out.

xxx@yyy.net:

66.150.45.42 does not like recipient.

Remote host said: 550 5.2.1 Mailbox unavailable. Your IP address 131.103.218.175 is blacklisted using SPAMCOP. Details: Blocked - see http://www.spamcop.net/bl.shtml?131.103.218.175.

Giving up on 66.150.45.42.

So, if you'll follow me here: 131.103.218.175 is blacklisted.  That IP address is mail01h.rapidsite.net.  But that's the mail server that's receiving the email (and relaying it to someone else - presumably one of the ISP's customers).  So it's refusing to deliver mail because it is blacklisted, itself!

Real Semaphores on PalmOS 5

It turns out it's fairly easy to implement real binary semaphores on PalmOS 5. This is really handy for folks that want to perform synchronization between their audio callback thread and their UI thread, for instance. Unfortunately, you have to access the semaphore from ARM-native code.

The trick is the SWP ARM instruction. This instruction swaps the contents of a register and a memory location, and it guarantees that this will be an atomic operation.

Here's some sample code in ARM assembly:

@ initialize a 4-byte word value to 1. That initializes your semaphore.

@ wait

@ r4 should contain an address that points to the semaphore.
.Lacquiresemaphore:
mov r5, #0
swp r5, r5, [r4] @ try to set the semaphore to 0
cmp r5, #1 @ if the previous value was 1, then we got it
beq .Lgotsemaphore @ this is a busy wait, but you could insert
@ an OS call - perhaps SysTaskDelay - to make it better
b .Lacquiresemaphore

.Lgotsemaphore:
@ do stuff

@ signal

mov r5, #1
str r5, [r4] @ reset the semaphore

Of course you can extend this example to implement more complicated semaphores as well.

The advantage of this versus a spin lock is that you don't need to know which thread you are executing in. With a 2-slot spin lock, you need to know if you are user #1 or #2.

Enjoy!

ActiveWords

Pretty cool piece of software.  Gerald's been using it to do some customer support, and it really speeds up entering canned responses, etc.  You basically can assign any set of keys to do certain tasks (using an optional action key to trigger the task).  Tasks are very flexible and can include things like running programs, web pages, pasting contents of text files, etc.

SPF has problems

I thought I was doing a good thing by adding SPF to my email server.  Unfortunately, I am now finding that there are some serious problems with this scheme.  The biggest one has no solution (that I know of) other than to disable SPF: If your ISP forces you to send email only through their SMTP server (lots of ISPs do this now), then your emails will all fail the SPF test because they originate from your ISP's SMTP server instead of your own.  This also occurs when you are travelling and hook up to a random WiFi hotspot.  Many of them funnel email through their SMTP servers.

Someone's written an article about these types of problems.  He's a bit extreme but has some good points.

The volcano display at the Mirage



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Cirque du Soleil show 'O' at Bellagio - before the start



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Very cool Palm-controlled flexible displays from nyxit.com!



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Ryan Sutton from Handmark



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John Chafee from SplashData



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Here I am at the NormSoft kiosk in PalmOne's booth at CES 2005. Come see us at booth #30,374!!



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There's little that pisses me off more than poor customer service.  Twice I have reported a pricing error to www.pricegrabber.com and twice they have responded with a completely irrelevant answer and have taken no action.  Seeing as their core business revolves around having accurate price listings, this is inexcusable, and I will switch to using other price comparison web sites.

http://www.cnn.com/2004/TRAVEL/12/25/flights.canceled/index.html

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Even the airlines are joining in on the Christmas Cheer. I got a coupon for up to $150 yesterday. The catch is that my luggage needs to remain lost for 5 days...


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ROTFL

I just had to share this support request...  I'll withhold the name to protect the ... err ... not so innocent.

"I just want to know if I can set Pocket Tunes to vibrate mode so my tunes will vibrate to the beat instead of playing music. I want to drop it down my pants and be happy all day!  Rock on dudes!"

Pocket Tunes Update

Pocket Tunes 3.0.6 is now available with lots of nifty new features, including support for M3U playlists.

I've also updated the Pocket Tunes automation API and the Pocket Tunes skin compiler.

 

Our November newsletter

Don't use blacklists!

Today we sent out a newsletter to all of our users.  It's a perfectly legitimate email sent to existing customers with clear unsubscribe instructions, and we completely honor all subscription/unsubscription requests.  We even process all bounce requests and remove emails that bounce 3 or more times.

Several hours later, SpamCop blacklisted us, and we got a slew of complaints from customers who weren't getting their order confirmations.  This is a perfect example of why blacklists are bad.  Do not use blacklists on your server!  If you use blacklists, you are likely blocking legitimate email because most of these blacklists make ill-informed decisions based on over-zealous user reports of spam.  There is no oversight and very little recourse for valid companies to contest the blacklisting.  For all we know, it could be one of our competitors reporting the spam.

All the user has to do is click the unsubscribe link, and we'll NEVER email them again, but yet they'd rather go through the trouble of filing a bogus spam report.  Go figure.

 

Don't Install the T3 DIA Compatibility PRCs on a T5

We've had half a dozen customers angrily email us that the DIA is no longer working on their T5 after installing Pocket Tunes.  It turns out they installed the T3 DIA compatibility PRCs.  The only solution that I know of is to perform a hard reset and restore your files except for those 2 PRCs.  Two problems here:

1. Why the hell did PalmOne let the T3 compatibility PRCs screw up the T5?

2. Why do customers insist on installing files for devices that they don't have?  (In the past, we've heard from customers who installed these files on their iQues and Zodiacs, too!)

If you're a Palm developer, it's another support nightmare to worry about.  Have fun!

NormSoft Acquires HBlogger

Well, this announcement is a little old, but I've been quite busy lately.  NormSoft recently acquired a suite of software products from the PalmOS company Hexlet LLC.  Among these products is HBlogger, a very nice PalmOS app for posting messages and photos to your blog.

We've also acquired TrafficStat and DialStat, two tools to track your data and voice usage on your PalmOS smartphone.

To see all of NormSoft's products, visit http://www.normsoft.com/products.shtml

 

Here's Mark Belliveau, Director of NormSoft, getting ready to enjoy a fun week with PalmGear on their 2nd annual cruise...

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