In the office, the quantity of blocked junk mail has increased significantly and is now running at 1/2 million blocked messages per month.
After observing that my personal domain has started to see an increase in junk mail sent to invalid addresses, I configured our mail system to differentiate between junk mail sent to valid internal addresses and invalid internal addresses.
The results have been a huge success, showing that 50% of all mail received is sent to invalid addresses, cutting the size of our junk mail queues in half [...]