An electronic message sent under the influence of excessive alcohol, usually regretted when sobriety returns.
When you write something on a desk for someone else to read later. Could be intentionally, for example writing a message to someone who sits in the same desk later in the day or unintentional, for example having someone forget to erase the answers for the test that they wrote on the desk or writing random crap on the desk.
Beanerous Brokus I: Thank god I received that D-mail, I nearly failed the test.
Beanerous Brokus I: Look at this D-mail I got, it says "You suck"