EmbeddingGemma 2: an open, lightweight multimodal embedding model
deepmind.google·6d ago
AI Engineering
Hacker News·Aug 3·5 min read
What DMARC Protects You From, and What It Does Not
TL;DR
DMARC is often misused as a spam and phishing filter, but it only verifies if the sender is authorized by the domain owner. Understanding its limitations is crucial to maintaining effective email security.
✦ Why It Matters
Review your email security strategy to ensure it covers areas beyond DMARC's capabilities.
Key Takeaways
- Understand DMARC's role: it verifies sender authorization, not content safety.
- Implement SPF and DKIM alongside DMARC for better protection.
- Monitor DMARC reports to identify unauthorized senders using your domain.
- Be aware of DMARC's limitations against lookalike domains and compromised accounts.
How It Works
DMARC operates by checking if either SPF or DKIM authentication aligns with the visible From address. If either method passes, DMARC confirms the message's legitimacy.
This alignment is crucial, as it ensures that the sender is authorized by the domain owner.
⚠ The Catch
DMARC does not protect against lookalike domains or display-name impersonation, allowing attackers to bypass its checks if they use valid SPF and DKIM configurations.