[derefr]

Have you considered creating a discussion platform where people can't post images, URLs / things that would be URLs if you added a URL scheme to them, ASCII-armored baseN-encoded anything, etc? For 99% of the discussion you want on the platform, text is all you need. For spammers and people who want to host porn, text alone is useless.

[sodality2]

Plenty of spammers rely on text, though. A good chunk of my spam folder is text only.

[derefr]

Likely text containing URLs, though, which your email client likely helpfully auto-formats into links. Which is why spammers would bother. They need you to go visit something to make money.

There are types of bulk unsolicited email/web-comments which involve text without links, but they aren't spam per se; they're (the initial bait emails for) scams.

(And the usual solution to scam postings on forums, is to prevent people from sharing any off-forum contact details, except maybe via forum private message. No Nigerian prince is going to run their whole scam through the forum; they want/need to convert you ASAP into having a non-intermediated conversation with them. So they won't bother with any forum where they can't stuff their email address / Telegram handle / etc into each post.)

[Induane]

I've been itching for an experiment; might be fun to make a modernized BBS system for people to deploy.