A valid SPF record can silently fail email authentication — here's why

·1 views

A common but hard-to-detect SPF failure occurs when a domain exceeds ten DNS lookups, a limit set by RFC 7208 that causes receivers to treat the entire SPF record as unusable rather than partially valid. Unlike syntax errors, this issue produces no warning in standard DNS tools or outgoing mail tests, making it invisible to most senders. The problem can be triggered by a third-party vendor quietly updating their own SPF record, pushing a domain over the limit without any change on the sender's side. The only reliable place to spot the failure is in DMARC aggregate reports, which many organizations do not actively monitor. The most straightforward fix is removing SPF includes for email services no longer in use, which immediately reclaims lookup budget at no cost.

Read the full story at DEV Community

This is an AI-generated summary. ShortSingh links to the original source for the complete article.

Discussion (0)

AI Boosts Individual Developer Speed but Can Slow Down Entire Teams

AI coding tools reliably increase individual developer output, but a 2025 analysis highlights how this does not automatically translate into faster team-wide delivery. Coordination costs — including duplicated work, decision drift, and ownership ambiguity — tend to grow as more code is produced faster by developers who lack visibility into each other's progress. A 2025 study of experienced open-source developers found that AI assistance actually slowed task completion on mature, familiar codebases, suggesting perceived and measured speed can diverge. The 2025 DORA report further characterizes AI as an amplifier that magnifies both an organization's strengths and its existing dysfunctions. Teams are advised to identify which coordination bottleneck is the true ceiling on throughput, rather than focusing solely on making individual contributors faster.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Developer builds CI-tested Cursor slash commands with behavioral evals and ship gates

A developer has released an open-source Cursor plugin that treats AI slash commands like production code, pairing each command with a formal skill contract and behavioral evaluations. Unlike typical prompt packs that rely on copy-pasted markdown, this system scores agent outputs as PASS, PARTIAL, or FAIL using predefined rubrics. A CI pipeline checks that critical safety and behavioral phrases remain present in skill files, failing the build if any are removed. The approach avoids expensive LLM-based review on every pull request, relying instead on cheap structural text fixtures. The plugin is available on GitHub under an MIT license and installs via Cursor's Plugins settings.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Soft-Fade-Out Pattern Offers IoT Compliance Fix Without Full Hardware Redesign

Engineers working with legacy IoT hardware face mounting pressure to meet cryptographic compliance standards such as CRA, DORA, NIS2, and NIST's post-quantum requirements, which deprecate RSA and ECDSA after 2030. A proposed approach called the 'soft fade-out' pattern avoids costly board redesigns by pairing existing silicon with a dedicated security co-chip that handles key storage, firmware signing, and encrypted network communication. The legacy chip continues performing its original functions — sensors, display, application logic — while the cheaper companion chip closes the compliance gap at the cryptographic boundary. This strategy addresses three common shortcomings of older embedded silicon: lack of hardware-isolated key storage, insufficient side-channel protections, and limited memory for running modern lattice-based post-quantum algorithms. However, the pattern does not resolve data-at-rest vulnerabilities on the legacy chip itself, meaning sensitive data stored in its own flash or SRAM would still require direct hardware-level remediation.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

From One VM to Per-Service LXC Containers: A Self-Hoster's Infrastructure Journey

A self-hosting enthusiast documented their evolution from running all services inside a single Docker-enabled VM to adopting Proxmox LXC containers on a per-service basis. The initial single-VM setup was fast to deploy but fragile, as any bad update or resource spike affected every service simultaneously. Splitting workloads into purpose-built VMs improved resilience and enabled Proxmox high-availability failover, but GPU sharing limitations exposed the approach's ceiling. The shift to one LXC container per service offered finer isolation, cross-node failover, and greater efficiency. The author frames each architectural stage as a deliberate tradeoff rather than a mistake, arguing that real infrastructure knowledge is gained by navigating the balance between consolidation and separation.

0 comments Read more at DEV Community