How do smaller regional providers filter?

Smaller and regional email providers typically lack the resources to build sophisticated filtering systems like Gmail or Microsoft. They rely on different approaches.

Third-party filtering solutions are common. Many small providers use SpamAssassin, Rspamd, or commercial gateways from Barracuda or Proofpoint to handle filtering.

Blocklist reliance is heavier among smaller providers. They may simply query Spamhaus and other blocklists without sophisticated additional analysis.

Less personalization means filtering is more uniform. Smaller providers often lack the data and resources for individual user-level filtering.

Stricter defaults sometimes apply because smaller providers cannot afford to manually investigate edge cases. They may err toward blocking rather than risk spam complaints.

Smaller harbors may have simpler inspection processes. Often they defer to trusted external authorities rather than conducting their own sophisticated analysis.