Moderation & Anti-Spam Tools

4 self-hosted open source alternatives in this category

Discourse

Modern, searchable discussion forums for communities

Open source forum software with real-time discussions, powerful moderation, SSO, and integrations—built for long-lived, searchable community knowledge.

Alternative to:

Zendesk+5

Lemmy

A federated link aggregator and discussion platform

14.2k

935

Last commit: 2d ago

Self-hosted, ActivityPub-based forum platform for communities, link posts, and threaded discussions with federation across the Fediverse.

Alternative to:

Reddit+4

Stalwart Mail Server

All-in-one secure mail server with modern spam filtering

11.1k

598

Last commit: 3d ago

Stalwart is an all-in-one mail server (SMTP/IMAP/JMAP) with built-in anti-spam/DMARC, web admin UI, and flexible routing for running your own email infrastructure.

Alternative to:

Microsoft Exchange Online+9

Misskey

Federated microblogging platform with rich social features

10.9k

1.5k

Last commit: 2d ago

Self-hosted ActivityPub social network server with customizable UI, reactions, drive storage, powerful moderation, and federation with Mastodon and other Fediverse apps.

Alternative to:

X (formerly Twitter)+4