Well, I really feel somewhat like an idiot right now. Yesterday I posted a review of Myster-e-Mail. Late last night or early this morning I received another payment from them (only 3 cents but it was a payment).
Today I am getting nothing but the fact that the domain has expired!
Myster-e-Mail seems to have vanished over night and I am disappointed - I really did enjoy receiving my small payments as surprises here and there.
I have seen this happen before where someone has simply forgotten to pay their domain fees so hopefully this will be the case and they will be back going strong again soon.