EExactVerify4d ago · 10 min readHow to Generate a DMARC Record for My DomainIf you send emails from your business domain, you need to know how receiving mail servers determine whether those messages are legitimate. Without proper email authentication, attackers can attempt toexactverify.hashnode.dev
MMuhammad Ali MughalOct 23 · 7 min readHow to Check SPF, DKIM and DMARC Records in 10 Minutes (and Fix the Common Mistakes)Here is a deliverability problem I see a lot: a business says its invoices "just stopped arriving," and nothing changed on their side. When you look at their DNS, you find two SPF records, a DKIM key resume-ai.hashnode.dev
VVũ Nhật LâmOct 13 · 11 min readAntino: A Backdoor With No C2 Server, Because Outlook and OneDrive Are EnoughSummary Cisco Talos has published its analysis of UAT-11587, a group it assesses as China-nexus with high confidence, targeting government bodies and policy organizations across Asia. As of July 2026:1blog.fiscybersec.com
SSunilOct 5 · 6 min readSPF, DKIM and DMARC Explained for DevelopersYou can write perfect password-reset HTML, pick the nicest email API, and still land in spam because you never published a TXT record. SPF, DKIM, and DMARC are the unglamorous DNS work that makes transunilsandhu.hashnode.dev
GGerwinOct 1 · 13 min readSPF, DKIM and DMARC Explained Without the MigraineEmail was built on trust. Specifically, on the assumption that nobody would lie about who they are. That assumption lasted about ten minutes. The protocol that moves your mail, SMTP, will happily let 1fuckit.hashnode.dev
FFaraz AhmadSep 17 · 7 min readBuild an SPF, DKIM & DMARC Checker API with Node.jsAn SPF, DKIM and DMARC checker needs to do more than report whether three DNS records exist. A domain can publish SPF yet have no DMARC policy, sign mail with DKIM but use an unexpected selector, or hstadiasoft.hashnode.dev
SSoulaymen YaakoubiAug 8 · 4 min readHow to Check SPF, DKIM and DMARC Without Leaving Your AI AssistantEmail authentication debugging is a lookup problem. Someone forwards you a bounce, and answering it means pulling a TXT record, counting SPF includes, chasing a DKIM selector through a CNAME chain, anplaindmarc.hashnode.dev
JJose PollmanAug 7 · 4 min readWhy your DMARC reports never arrive (and why Gmail can't be your rua address)There is a failure mode in DMARC that is worse than a misconfiguration, because a misconfiguration at least shows up somewhere. Your record is valid. Every checker says it's fine. And you receive nothnotspoofed.hashnode.dev
JJose PollmanAug 6 · 5 min readSPF passed. DKIM passed. DMARC failed. Nothing is broken.This header block is where most people's understanding of email authentication falls apart: Authentication-Results: mx.google.com; spf=pass smtp.mailfrom=bounce@esp-vendor.net; dkim=pass header.d=notspoofed.hashnode.dev
CCanny PigeonsJul 23 · 5 min readHow to set up DMARC and DKIM for MailchimpMailchimp sends your campaigns from its own servers, so by default the DKIM signature says d=mailchimp.com and the SPF check uses a Return-Path on mailchimp.com. Both checks pass — but for Mailchimp'scannypigeons.hashnode.dev
