Will you check the headers on the message for me? (There may be an option for "view original headers" or something like that.) You should be able to tell from there if the delay was caused by WikiTree or your e-mail provider. They may have received the message two hours before they delivered it to you.
Unfortunately, we have trouble with e-mail providers holding messages as suspected spam. I see that you're account is with yahoo. Yahoo is one of the worst.