An support system server (100) accepts, for each board related to crisis response activity, browsing of one or more messages registered in the board and registration of a message in the board. When a transmission source of a received e-mail is an e-mail address of a user of the board, the support system server (100) registers a message included in the e-mail in the board. When a new message is registered in the board, the support system server (100) distributes an e-mail including the message to the e-mail address of the user of the board.