Nobody in the forum will be able to say whether or not it is fake - even if seeing and handling the bag, it would be difficult. Have you used google to check the serial number and what to look for in a genuine bag?
Best bet is to take it to a Mulberry stockist.
Ebay do use the authentication process for more expensive bags.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)
