Aye. I naively thought that classified messages from one Western defence ministry to another would be transmitted in something a bit more secure than an ordinary MTA.
The emails were intended for the US military, which uses the domain name ".mil". But they missed out the letter i, and so the messages went instead to the West African nation of Mali.
I don't think many people would be legitimately sending mail to .ml domains, especially not to domains that match a top level domain in .mil