This is a chance to share some of my own personal horror stories.
It was 2000 and I was working at my second job after college. I was mostly coding for the PalmOS but dabbled a bit in Classic ASP (VBScript).
One day, I was given the task of writing a script to email several hundred people using an off-the-shelf COM object for email tasks.
The pseudo-code of the script went something like this:
dim emailListdim emailSender 'The 3rd-party componentemailSender.StartSession()for each person in emailList emailSender.From = emailList.email emailSender.Subject = "Whatever" emailSender.Body = "Foo" emailSender.SendnextemailSender.EndSession()
Pretty straightforward, right?
What I didn’t realize was that, during a single session, setting the From address actually did an append rather than overwriting the current value.
That meant that, the first time through the loop, the email went to the first person. The second email went to the second person and the first person. The third email went to the third person, second person, and first person. And so on.
Luckily, I was on the list so I immediately noticed that I was getting multiple emails. Unfortunately it ran through half the list before I was able to get IIS stopped.
As you can imagine, we had a lot of really pissed of replies.