Setting Up DKIM for Your Domain: DNS Records, Testing, and Troubleshooting
Set up DKIM for your domain with correct DNS records, selector guidance, testing commands, key rotation, and fixes for common failures.
Aug 15, 202620 min read
Email Authentication
140 articles on email authentication.
What Is SPF and Why Is It Important for Email?
Learn what SPF is, how SPF DNS records work, why it matters for email security and deliverability, and how to configure and test it correctly.
Aug 15, 202622 min read
What Is DMARC? How Email Authentication, Alignment, and Policies Work
What is DMARC? Learn how SPF, DKIM, alignment, DNS policies, reports, and enforcement protect your domain from email spoofing.
Aug 15, 202623 min read
What Is DKIM? A Developer’s Guide to Email Authentication
What is DKIM? Learn how DKIM email signatures, DNS selectors, key rotation, and DMARC alignment protect messages and support deliverability.
Aug 15, 202623 min read
What Are Transactional Emails? Definition, Examples, and Delivery
What are transactional emails? Learn how automated, event-triggered messages work, differ from marketing email, and deliver reliably.
Aug 15, 202620 min read
Transactional vs Broadcast Email: Differences That Matter
Transactional vs broadcast email explained: learn when to use each, how consent, deliverability, DNS, retries, and unsubscribe rules differ.
Aug 15, 202623 min read
Why Is My Email Going to Spam? Causes, Tests, and Fixes
Why is my email going to spam? Diagnose authentication, reputation, content, list quality, and sending issues with practical fixes.
Aug 14, 202620 min read
How to Fix DMARC Policy Bounces: A Technical Guide
Fix DMARC policy bounces by diagnosing SPF, DKIM, and domain alignment failures, validating DNS records, and safely restoring delivery.
Aug 14, 202620 min read
How to Fix ISP Blocks: A Practical Email Deliverability Guide
Learn how to fix ISP blocks with a proven process for diagnosing SMTP errors, repairing DNS authentication, reducing complaints, and restoring delivery.
Aug 14, 202622 min read
How to Fix Spam Complaints: A Technical Guide for Email Senders
Fix spam complaints with practical steps for authentication, consent, list hygiene, unsubscribe flows, and sender reputation recovery.
Aug 14, 202621 min read
How to Fix Soft Bounces: Diagnose SMTP Deferrals and Restore Delivery
Learn how to fix soft bounces by decoding SMTP 4xx errors, repairing authentication, managing retries, and protecting sender reputation.
Aug 14, 202624 min read
How to Fix Hard Bounces: A Developer’s Troubleshooting Guide
Learn how to fix hard bounces by decoding SMTP errors, validating recipients, repairing DNS authentication, and protecting your sender reputation.
Aug 14, 202621 min read
What Are Email Bounces and Spam Complaints? A Developer’s Guide
Learn what email bounces and spam complaints mean, why they hurt deliverability, and how developers can prevent, monitor, and handle both.
Aug 14, 202623 min read
How to Test SMTP Errors: A Practical Guide for Developers
Learn how to test SMTP errors with live sessions, SMTP reply codes, DNS checks, retries, and API diagnostics before delivery problems reach users.
Aug 13, 202622 min read
SMTP Codes: What They Are and How to Troubleshoot Them
Learn what SMTP codes mean, how to separate temporary from permanent failures, and troubleshoot delivery, DNS, TLS, and reputation issues.
Aug 13, 202625 min read
Google Sender Reputation: How to Improve Gmail Deliverability
Improve Google sender reputation with authentication, list hygiene, compliant unsubscribe flows, and Postmaster Tools monitoring for Gmail delivery.
Aug 13, 202620 min read
Sender Reputation Lookup: Check Your Email Domain and IP Health
Use a sender reputation lookup to check domain, IP, blocklist, and mailbox-provider signals, then fix the issues hurting email delivery.
Aug 13, 202620 min read
Why Email Open Rates Are Not Accurate—and What to Measure Instead
Email open rates are not accurate by design. Learn how pixels, privacy proxies, caching, delivery, clicks, and conversions reveal real engagement.
Aug 13, 202621 min read
Why Are My Emails Landing on the Suppression List?
Why are emails landing on a suppression list? Diagnose bounces, complaints, opt-outs, bad data, and authentication failures before sending again.
Aug 13, 202621 min read
Why Are My Emails Going to Spam? A Developer’s Troubleshooting Guide
Why are my emails going to spam? Diagnose authentication, reputation, content, and sending problems with this practical developer guide.
Aug 13, 202621 min read
Domain Not Verifying? A Developer’s DNS Troubleshooting Guide
Domain not verifying? Diagnose TXT, CNAME, SPF, DKIM, and DNS propagation errors with practical commands and fixes for email sending domains.
Aug 12, 202618 min read
What If an Email Says Delivered but the Recipient Has Not Received It?
Learn why an email says delivered but is not received, how SMTP delivery works, and the DNS, header, and inbox checks that pinpoint the issue.
Aug 12, 202621 min read
What Email Addresses to Use for Testing Transactional Email
Learn which email addresses to use for testing transactional email, from local inboxes and real providers to deliverability tools and test domains.
Aug 12, 202621 min read
Email Warm-Up: How to Build Transactional Sending Reputation Safely
Learn email warm-up for transactional mail: authenticate domains, ramp volume safely, monitor bounces, and protect inbox placement.
Aug 12, 202622 min read
Apple Branded Mail Setup: DNS, DMARC, and Verification Guide
Set up Apple Branded Mail with the right DMARC policy, DNS verification, brand assets, testing workflow, and troubleshooting steps.
Aug 12, 202622 min read
How to Avoid the iCloud Spam Folder: A Developer’s Guide
Learn how to avoid the iCloud spam folder with aligned SPF, DKIM, and DMARC, clean lists, stable sending, and practical troubleshooting.
Aug 11, 202621 min read
How to Avoid Gmail’s Spam Folder: A Developer’s Guide
Learn how to avoid Gmail spam folder placement with SPF, DKIM, DMARC, clean lists, compliant headers, reputation monitoring, and testing.
Aug 11, 202623 min read
How Do Dedicated IPs Work for Transactional Email?
Learn how dedicated IPs work for transactional email, when to use them, how IP warming works, and how to protect deliverability.
Aug 11, 202620 min read
2048-bit DKIM: Do You Need It for Email Delivery?
Do you need 2048-bit DKIM? Learn when 1024-bit is acceptable, how DNS limits affect setup, and how to verify DKIM for reliable delivery.
Aug 11, 202619 min read
Audience Hygiene: How to Keep Email Lists Clean and Deliverable
Audience hygiene keeps invalid, disengaged, and unsubscribed contacts out of sends. Learn validation, suppression lists, segmentation, and monitoring.
Aug 11, 202623 min read
Email Domain Audit: The SPF, DKIM and DMARC Checklist That Actually Protects Deliverability
Run an email domain audit that goes beyond DNS records. Fix SPF, DKIM, DMARC alignment, list hygiene, and bulk-sender compliance.
Aug 9, 202619 min read
Email Deliverability Expert: How to Hire, Vet, and Work With One
Learn what an email deliverability expert does, when to hire one, how to vet their skills, and how to fix authentication, reputation, and inboxing.
Aug 8, 202623 min read
Email Deliverability Survey: A Practical Audit for Better Inbox Placement
Use this email deliverability survey to audit authentication, list quality, sending patterns, and engagement—then fix the issues hurting inbox placement.
Aug 8, 202619 min read
Email Deliverability Consultant: How to Hire One and Fix Inbox Placement
Hire an email deliverability consultant with confidence: audit authentication, reputation, list quality, and sending practices that affect inbox placement.
Aug 8, 202621 min read
Email Deliverability Support: Diagnose, Fix, and Prevent Inbox Problems
Email deliverability support explained: diagnose DNS, reputation, bounces, and complaints, then build a plan to restore inbox placement.
Aug 8, 202618 min read
Transactional Email Plan: How to Choose, Set Up, and Scale
Choose a transactional email plan with the right volume, pricing, authentication, event handling, and deliverability controls for your app.
Aug 8, 202621 min read
Transactional Email Policy: How to Define, Implement, and Enforce It
Create a transactional email policy that separates product messages from marketing, protects deliverability, and gives teams clear sending rules.
Aug 8, 202624 min read
Email Deliverability Policy: A Practical Template That Protects Your Inbox Placement
Build an email deliverability policy with authentication, consent, list hygiene, monitoring, and a worked template for reliable sending.
Aug 7, 202621 min read
Transactional Email Plugin: How to Set Up Reliable WordPress Delivery
Set up a transactional email plugin for WordPress, authenticate your domain, test delivery, and troubleshoot emails that fail or reach spam.
Aug 7, 202623 min read
Email Authentication Error: Fix SPF, DKIM, and DMARC Failures
Fix an email authentication error with a practical SPF, DKIM, and DMARC checklist, DNS record examples, header checks, and troubleshooting steps.
Aug 7, 202620 min read
Transactional Email Meaning: What It Is, Examples, and How to Send It Reliably
Learn the transactional email meaning, how it differs from marketing email, and how to send receipts, password resets, and alerts reliably.
Aug 7, 202620 min read
Email Deliverability Checklist: The Practical Guide to Reaching the Inbox
Use this email deliverability checklist to authenticate sending, protect reputation, clean lists, reduce complaints, and diagnose inbox issues.
Aug 6, 202624 min read
Transactional Email Definition: What It Is, Examples, and Setup
Learn the transactional email definition, how it differs from marketing email, common examples, authentication setup, compliance, and testing.
Aug 6, 202619 min read
SMTP Relay Address: How to Find, Configure, and Test It
Learn what an SMTP relay address is, choose the right host and port, configure TLS and authentication, and test reliable email delivery for apps.
Aug 6, 202620 min read
Sender Reputation Meaning: How to Build Trust and Reach the Inbox
Learn sender reputation meaning, what affects inbox placement, and how to improve domain and IP trust with authentication, list hygiene, and monitoring.
Aug 6, 202622 min read
DMARC Record Format: Syntax, Tags, Examples, and Setup
Learn the DMARC record format, required syntax, every important tag, rollout steps, troubleshooting tips, and copy-ready DNS examples.
Aug 5, 202617 min read
Email Deliverability Assessment: A Practical Audit You Can Run
Run an email deliverability assessment that finds authentication, list, reputation, and content problems—and proves your fixes improved inboxing.
Aug 5, 202620 min read
DMARC Record Published: How to Add, Verify, and Enforce It
A DMARC record published correctly is only the start. Learn exact DNS TXT syntax, testing steps, alignment checks, and a safe enforcement rollout.
Aug 5, 202618 min read