Something that I've noticed about email notifications, at least when I receive them, is that they may or may not be arriving at the same time that others receive them.
One of my caching buddies frequently calls me to see if I'm going to find "the new cache that just came out". he frequently receives email notifications before I do. Sometimes there can be a long lapse in their arrival in my inbox.
Just wondering out loud, here.......
Maybe not all notifications are sent at the exact same time?
This is absolutely the case. I started hidng just this past week. On my second hide, one of the early logs questioned how the cache "popped" on his device, he left the house within 10 minutes, drove a short distance to the site, found the cache, and found that he had been beaten by several minutes (maybe more).
I absolutely did not inform anyone, nor do I even know the FTF cacher. So, this scenario can be the ONLY explanation.