Ugh, lockout must be pretty frustrating. Receiving one message could be worth as much as sending 1000 messages when valued by conversion to the spam end-goal. I

Ugh, lockout must be pretty frustrating. Receiving one message could be worth as much as sending 1000 messages when valued by conversion to the spam end-goal. It's also a less obvious technique and one that's more difficult to block. Clearly the algorithm is not as precise as it should be, but I'm sure this mechanism is preventing a lot of abuse even though it blocks some normal use.