I always write something like 12/14 when I send out my Christmas cards. Doesn't mean that I actually sent them out on time this year.
Now if the postage is dated 1/25, it's still only 3 1/2 business days. Big companies alot of times have bulk mailing rates. Was it definately first class, or does it say something else? Maybe stuff only gets mailed out once it's piled high enough.