Blogs
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DMARC
How to Move Your DMARC Policy From p=none to p=reject Without Breaking Mail
A practical step-by-step guide for safely upgrading your DMARC policy from p=none to p=reject without disrupting legitimate email.
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DMARC
How External Domains Can Send Email as Your Organization (And Why It Matters for BEC Risk)
Any external domain can send email claiming to be from your organization. Here is what that means for your BEC risk, how to detect it using DMARC aggregate reports, and what to do about it.
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DMARC
How External Domains Can Send Email as Your Organization (And Why It Matters for BEC Risk)
Any external domain can send email claiming to be from your organization. Here is the real impersonation and BEC risk this creates, how DMARC aggregate reports surface the exposure, and what to do before attackers exploit it.
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SPF
How to Fix SPF Permerror: Too Many DNS Lookups
Your SPF record is returning permerror because it triggers more than 10 DNS lookups. Here is how to count lookups, flatten your SPF record, and restore email authentication.
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DMARC
What is the Difference Between Mail-From and From Header in Email?
The Mail-From (RFC 5321) tells servers who delivered the email. The From header (RFC 5322) tells recipients who sent it. DMARC checks the From header domain, which is why SPF pass does not guarantee DMARC pass.
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99.8% of Mail Servers Still Accept Unencrypted Email. What Practitioners Should Know in 2026
A measurement study of 366,215 MX servers found that 99.8% still accept unencrypted email. Here is what practitioners need to know about TLS enforcement vs. STARTTLS availability.
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DMARC
Why Your DMARC p=reject Policy Does Not Block Mail (And What It Actually Does)
Your DMARC p=reject policy tells receiving mail servers to reject forged email, but it does not block mail from your own server. Here is what actually happens.
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DMARC
Why Safe Sender Lists Can Override Your DMARC Policy
Safe sender lists in Microsoft 365 assign SCL -1, which outranks DMARC authentication results. Here is what actually happens and how to check your configuration.
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SPF
Why Your SPF Record Suddenly Stopped Working (Even Though You Did Not Change Anything)
SPF suddenly failing even though nothing changed? Here are the hidden causes and how to diagnose them quickly.
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DMARC
Why DMARC Alignment Fails on Forwarded Emails (And What to Do About It)
When forwarded emails fail DMARC checks, the problem is almost never the sender. Learn what reshaping does to SPF, DKIM, and DMARC alignment.