I semi-regularly get support emails for them. If i'm in a good mood and see the email as it comes in, i'll tell them the correct email to use (no one has ever thanked me for that, as it happens). Normally I just ignore them, or don't notice them for a few days.
I find it mildly amusing when there's a series of emails from the same person with panic escalating over a few hours.
"Where is my project?"
"I need this for my report in the morning!"
"I'M GOING TO SUE YOU!"