Can you report and get a mail in the box shut down or deleted ??
Your post is rather vague, but I will assume that perhaps there is a bad actor who has installed Mail-in-a-Box and is using it for unsolicited email?
If so, your best recourse is to report the spam to spamcop.net. You can also do a WHOIS on the IP address and send an abuse report to the abuse contact.
@alento Also an of topic question if you reply to a bot catchall/Acceptall email will the emails you’ve sent be saved in the bot inbox or will it delete them ??