Ask HN: Spanish text appended to Amazon automated mail

I have refunded my order on Amazon.co.uk and received a confirmation email with the following subject line: "Important Information about your Amazon.co.uk Order #205-[redacted]-[redacted]q ahorita estoy q me quedo dormido escribiendo o en meido proceso de lo cansado q estoy"

At the end of the message they write that "Please note: this is an auto generated e-mail and we cannot read your answers reply."

So how did this funny subject line get there?