Alphabetical spammers

There have been a couple posts recently about a paper presented at the Fifth Conference on Email and Spam (CEAS). The paper showed how addresses beginning with different letters get different volumes of spam.
But this post is not really about the paper, although it is an interesting academic review of spam, it is more about a memory that the discussions triggered.
Long ago I was handling the abuse desk at the very large network provider. This was in the days before Feedback loops, so every complaint was an actual forwarded email from a recipient. Generally, we saw a couple dozen complaints about any individual spam problem. Not a huge volume by any means, but that meant that any volume of complaints was significant.
One afternoon I started seeing a spike in complaints about a customer who never received complaints before. I started looking a little deeper and discovered we had around 50 complaints about this mailing, many from people I knew, and all from individuals at domains that started with A. This was one of the few times we actually pulled the plug in the middle of a mailing.
I still remember going to my boss suggesting this was something to take action on now because we had over 50 complaints and they were still in the A‘s! The customer was mortified that the guaranteed opt-in list they purchased was so bad and promised never to spam again.
Have a good weekend everyone.