Not the same kind of loop, but a few years ago I had to quickly fix email sending in some PHP service. Being rusty in PHP, I at least managed to write a for loo

Not the same kind of loop, but a few years ago I had to quickly fix email sending in some PHP service. Being rusty in PHP, I at least managed to write a for loop iterating over the list and send mails. Or so I thought. I had forgot "$" in front of the "i" in the for-header, making it never terminate, since of course that's still valid php. Luckily it was only my private email in the test-list. But I still got so many thousands of mails my Gmail account was blocked for days. Also lucky this didn't affect the delivery of our future mail (not blacklisted).