I used to work at a place that blocked a significant fraction of incoming Dutch emails. Eventually we figured out it rejected any message with "kunt" ("he/she can"), which is not exactly uncommon. Apparently they were flagged as deliberate attempts to circumvent the profanity filter.
Do you want to block attempts to skirt the profanity filter? How to you avoid reintroducing the Scunthorpe problem?
Jeez, darn are all mild forms of expletives, should they be blocked? What about bloody? That many anglophones would go to if you couldn't swear?
Surely if you can't use those, people are just going to say gosh instead, or Smeg or frel. Should they also be banned. Swear words exist for a reason, you can perhaps get rid of the harshest forms, you are never going to remove the need or desire for people to swear though.
