[otmjmzpj] Exponentially rare messages

Send messages to a recipient at exponentially increasing intervals of time: e.g., in 1 week, 2 weeks, 4, 8...  The intervals increase because, over time, the recipient is less likely to care about the message-precipitating event in the past.  Let the sender control the two parameters in A*exp(r*t).

This might be a voluntary or regulatory means for controlling marketing e-mail and spam.