Gmail Tip: Sending empty messages

Official Gmail Blog: Tip: Sending empty messages

If you try to send an email using Gmail with only text in the subject line, Gmail would always prompt you to add in body text.

This is to make sure that you have not forgotten to insert the body text as most emails have body text.

Now, however, you can add "EOM" or "(EOM)" at the end of the subject line (short for End Of Message), and Gmail will silently send the message without the unnecessary prompt.