AutoSPF Blog

Foundational

AutoSPF’s Complete Guide: How to Add an SPF Record in Namecheap
ByBrad Slavin December 17, 2025December 17, 2025 Reading Time: 5 minutes

In today’s digital world, securing your email domain against spoofing, phishing, and spam isn’t just a technical best practice — it’s essential for protecting brand reputation, ensuring deliverability, and preserving trust with your customers and partners. One of the foundational email authentication protocols that every domain owner should implement is SPF, or Sender Policy Framework….

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Intermediate

How to set up SPF for Avanan– A step-by-step guide
ByBrad Slavin December 16, 2025December 17, 2025 Reading Time: 5 minutes

Avanan is a cloud-native email security platform that helps secure email in Microsoft 365 and Google Workspace. Unlike traditional gateways, it connects directly via APIs; so, it doesn’t sit in your mail servers and consume resources. This way, Avanan can scan emails once they land in your inbox, but before you open or interact with…

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Foundational

Complete Guide to Setting Up FreshMail DKIM and SPF Records
ByBrad Slavin December 16, 2025December 16, 2025 Reading Time: 7 minutes

In today’s email ecosystem, ensuring your messages are authenticated and trusted by recipients isn’t just a nice-to-have — it’s essential. Every day, millions of emails are sent for marketing, notifications, and transactional purposes. But without proper authentication, your carefully crafted messages could land in spam folders — or worse, be blocked entirely. At AutoSPF, we…

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Advanced

How Can I Identify SPF Include Loops Or Recursive Includes With A Validator?
ByBrad Slavin December 15, 2025December 15, 2025 Reading Time: 11 minutes

Use a DNS-aware, graph-based SPF validator that expands every include/redirect into an explicit include graph and runs cycle detection (e.g., DFS with a recursion stack or Tarjan’s SCC), guarded by lookup/depth limits and memoized caching, to reliably identify SPF include loops and recursive includes. SPF loops occur when one domain’s SPF record includes (or redirects…

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Intermediate

Why does my SPF record syntax exceed the 255-character limit and how do I fix it?
ByBrad Slavin December 15, 2025December 15, 2025 Reading Time: 10 minutes

Your SPF record “exceeds 255 characters” because DNS TXT records cap each quoted character-string at 255 bytes (per RFC 1035) and long SPF policies must be stored as multiple quoted strings that the resolver concatenates; you fix it by splitting the SPF value into ≤255‑byte chunks within a single TXT record (or refactoring to shorten…

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Foundational

What is SPF flattening, and why is it important?
ByBrad Slavin December 12, 2025December 17, 2025 Reading Time: 6 minutes

If you only have a couple of email services, let’s say one or maybe two servers that send emails on your behalf, maintaining your SPF records is pretty straightforward. But in reality, that’s not really feasible, as most organizations have more than a handful of servers and third-party services that use their domain on your…

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Advanced

When should I avoid SPF flattening and rely on alternative authentication strategies?
ByBrad Slavin December 12, 2025December 12, 2025 Reading Time: 14 minutes

You should avoid SPF flattening whenever your sending footprint is dynamic (CDNs, cloud ESPs with fast-changing IPs), when flattening would inflate DNS beyond safe sizes (especially with IPv6 or many includes), when forwarding/relaying is common (better solved with SRS, DKIM, or ARC), during ESP migrations or strict compliance/key‑rotation regimes, in multi‑tenant/delegated subdomain designs, and whenever…

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Intermediate

Complete Guide by AutoSPF: How to Configure SPF and DKIM for Exclaimer and Secure Your Email Domain
ByBrad Slavin December 12, 2025December 12, 2025 Reading Time: 7 minutes

Email authentication is one of the most critical foundations for protecting your brand and domain from spoofing, phishing, and deliverability problems. In 2025, major email providers like Google, Microsoft, and Yahoo increasingly treat SPF, DKIM, and DMARC as must-haves. Without them, legitimate emails may be flagged as spam, rejected outright, or fail to reach the…

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Intermediate

How can I find which sending IP produced the spf=permerror result in message headers?
ByBrad Slavin December 11, 2025December 11, 2025 Reading Time: 15 minutes

To find which sending IP produced spf=permerror in message headers, locate the Authentication-Results line that reports spf=permerror, match its authserv-id to the Received or Received-SPF header added by that same host, and extract the client IP noted there (or, if absent, select the first external connecting IP in the Received/X-Received chain that immediately precedes the…

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Advanced

Office 365 SPF Best Practices: Protecting Your Domain From Spoofing
ByBrad Slavin December 11, 2025December 15, 2025 Reading Time: 15 minutes

The best-practice SPF configuration for Office 365 is to publish a single TXT record of v=spf1 include:spf.protection.outlook.com -all for your primary domain, then explicitly add ip4:/ip6: mechanisms for any on‑premises egress IPs and include: mechanisms for each third‑party sender, while coordinating SPF with DKIM and DMARC, testing against the 10‑lookup limit, and continuously monitoring and…

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