One of my favorite quick hacks is EOM (End of Message).
If you send someone or a group of people an email you can write a short message in the Subject line and them type EOM at the end. The person reading the subject line in their email knows that there is no text in the email and that they don’t even need to bother opening it. It essentially turns an email into a text message.





Here is an example:
Running late. Be home in 1 hour. XOXO EOM