I have started this morning (25/05/14) the adventure "Horseback". I sent the army immediately and meanwhile I visited the adventure island to start collecting the 2 collectibles on the map. Everything seemed fine as I got one cauldron and one adamantium, which the screen showed they would have been delivered once back to my island. Went back to check the mail (I had the mail logo next to my profile picture for new mails) but nothing had been delivered; I had as last mail in date one combat report dated 20/05/2014.
Was it a problem of my browser (it needed refresh or else) or was it a bug?
Just to explain, after that I have tried to refresh the page and reload the tab but still my mail doesn't show anything that could have been delivered today.