EDIT -- it lookslike there is a new penalty in place for posting more than 4 top level posts per day... as a way to not trigger this, users could simply have one post per month, where users reply with pgp encoded messages.

SO if you wanted to send a message to me, you would go reply here https://steemit.com/message-sigmajin/@sigmajin/example-message ... since replies close after one month, users would have to open a new message box every month.. idk if thats a reasonable burden for the system...