Guide · EmailBIMI Explained: Show Your Logo in the Inbox (Requirements and Setup)What BIMI is, what it requires (DMARC enforcement, SVG Tiny PS logo, VMC or CMC certificate), how the DNS record looks, and which mailbox providers display it.6 min readGuide · EmailCheck Your Email Domain Setup (MX, SPF, DKIM, DMARC) in 15 MinutesA beginner's walkthrough to check that your business email domain has the right MX, SPF, DKIM and DMARC records, with free tools and plain-language fixes.7 min readGuide · EmailDKIM Setup and Troubleshooting: Selectors, Key Length, RotationHow DKIM selectors and keys work, how to publish and test a record, choose key length, rotate safely, and diagnose the common reasons dkim=fail shows up.7 min readGuide · EmailDMARC Rollout: From p=none to quarantine to reject, SafelyA staged DMARC rollout plan: publish p=none, read rua reports, fix alignment, ramp pct, set a subdomain policy with sp=, and reach p=reject without losing mail.7 min readGuide · EmailEmail Blacklist Removal Guide: Find the Cause, Get Delisted, Stay CleanLearn how DNS blocklists work, how to check IP and domain listings, fix the root cause first, request delisting, and prevent repeat listings on your mail server.8 min readGuide · EmailEmail Bounce Codes Explained: 4xx vs 5xx and Enhanced Codes (5.1.1, 5.7.1)Decode SMTP reply codes and enhanced status codes in bounce messages: temporary 4xx versus permanent 5xx, what 5.1.1, 5.7.1, 5.4.1 and others mean, and what to fix.7 min readGuide · EmailEmail Going to Spam? A Step-by-Step Diagnostic ChecklistWork through authentication, blocklists, reverse DNS, sending reputation and content to find out why your email lands in spam, and what to fix first.6 min readGuide · EmailFix SPF "Too Many DNS Lookups" (Permerror): Count, Trim and FlattenYour SPF record can only trigger 10 DNS lookups. Learn what counts, how to count them, and how to fix a permerror by pruning, splitting and flattening.8 min readGuide · EmailGoogle Workspace DNS Records: MX, SPF, DKIM and DMARC SetupThe DNS records a Google Workspace domain needs for working, authenticated email: MX, SPF include, DKIM key, DMARC, and how to verify each one.6 min readGuide · EmailMicrosoft 365 DNS Records: MX, SPF, Autodiscover, DKIM and DMARCThe DNS records Microsoft 365 and Exchange Online need for mail flow and authentication: MX token, SPF include, Autodiscover, DKIM CNAMEs and DMARC.6 min readGuide · EmailMTA-STS and TLS-RPT Guide: Enforce TLS for Inbound EmailHow to set up MTA-STS and TLS-RPT: the DNS TXT records, the policy file on mta-sts.example.com, testing, enforce mode, and how to read TLS reports.6 min readGuide · EmailMX Records Explained: Priority, Backup Servers and Null MXWhat MX records do, how priority works, why backup MX servers are risky, the rules for targets, and how to publish a null MX for domains that never receive mail.7 min readGuide · EmailReverse DNS (PTR) for Email: Why It Matters and How to Set It UpHow PTR records and forward-confirmed reverse DNS affect email delivery, how to check them with dig, and how to set matching rDNS, HELO and A records.6 min readGuide · EmailSPF, DKIM and DMARC Explained: A Complete Setup and Rollout GuideSet up SPF, DKIM and DMARC correctly, understand alignment, move safely from p=none to reject, and read reports without breaking legitimate mail.8 min readGuide · EmailTransactional Email DNS Checklist: Subdomain, Return-Path, DKIM, TrackingThe DNS setup for sending transactional email through a provider: a dedicated subdomain, return-path CNAME, DKIM, SPF, DMARC alignment and a tracking domain.7 min readGuide · EmailWarming Up a New Email Domain or IP: An Honest GuideHow to build sending reputation for a new domain or IP: set up authentication first, start small with engaged recipients, ramp gradually, and what warm-up services can and cannot do.6 min read