Originally Posted by
Berto
In the end I probably should have checked to see if I could have purchased an Online-Ticket vs. via Post, but for some reason I do not think that was an option.
As far as I know, Online tickets are virtually always available if you use trains in Germany, or DB trains going abroad. Exception is if you start your trip abroad - so Brussels-Frankfurt-Brussels is not available as an Online-Ticket, whereas Frankfurt-Brussels-Frankfurt is.