Yahoo! (Can’t) Mail
I tried to send a message though Yahoo! Mail and was presented with a test of typing the following string into the text box so that I could continue to send mail and prove that I wasn’t a spammer.

I found out how sucessful I was when I got the following error:
Character String Verification Error
You need to pass the verification test to send any more email.
Your message has not been sent and will not be saved.
Where was the text of my message? Gone to the ether. Hitting the back button only served to show me the empty “Compose Message” screen. So I decided to try again.

And failed once again. Another email vanished.
What kind of inane corporate policy is this, that you willfully delete your customers projects that they were working on, because you suspect that they might not be the person typing on the computer? Has anyone actually made it though one of these tests before? Will Yahoo! evetually stop asking me?

I recently encountered one of these things. They are next to impossible to tell what characters are displayed. Ridiculous. I stared for probably 3 straight minutes trying to figure out what it was, and I almost hit submit when I noticed that it, too, was CASE-SENSITIVE! In little tiny letters, hardly noticeable, was the warning. Ridiculous.
So, I’ve done this before and had complete success. Maybe you don’t know it, but you actually are a spam bot.
how to pass this test
Beeing a Mac user for more than 10 years I totally agree with that