Lifehacker’s Brad Isaac suggests using “EOM”, a quick way to indicate the end of a message, to save your addressees’ time. How? Put the whole message in the subject, and end with “EOM” (example: “Will be in the office @ 3:30 EOM”), which indicates the reader need not waste time opening your email.
Even used in the body of the message, it can help, since many email programs give the reader a short preview of the message. If the reader sees EOM, he or she can act on the message and move on.
Sure, you will get a lot of questions at first, but once everyone is in the know, it should help speed things up!
How “EOM” Makes Your Email More Efficient | Lifehacker