メールでの投稿を複数のカテゴリに同時に許可しますか?

Sending the same email to multiple email lists is quite common (e.g. to a low-traffic announcement-only list and a high-traffic discussion list) and some people want to replicate that on a forum. I’m sure it’s been mentioned here a few times, though this is the only exact match I found today:

「いいね!」 1