Back last year, people came up with the idea to use the mailbox to transport Filled Festive Mugs and make them lose duration. I tried to use the same method this year to no avail. Apparently, Blizzard fixed it.
However, I did notice that, while the Mug is in the mail, it doesn't lose it's current duration, so you can keep them suspended BETWEEN two characters and withdraw them when needed. While this isn't as useful as the old version, it will still allow people to "postpone" the duration on the beer.
I know that it's a day too late for people to use this method, but I felt like saying something. Also, if anyone managed to find a new way to lose the time duration on the mugs, I'd love to know...