EOM means End Of Message
EOM (or better yet (EOM)/<eom>) is used to indicate that the message is not larger.</eom> It is used on Twitter and in MSN and SMS messages, but it can also be used in the e-mail. If you put EOM in the subject of an e-mail message, the recipient knows that the rest of the message does not need to be read. So it is useful for small messages.