✉PowerMTA.inEmail Infrastructure & Deliverability
LATESTGmail Sender RequirementsSMTP TLS ExplainedPTR & Reverse DNSDeliverability ChecklistAuthentication Troubleshooting
Featured technical guide

Gmail Sender Requirements: SPF, DKIM, DMARC, TLS and Unsubscribe Explained

Understand the systems behind modern email delivery with practical explanations, configuration guidance and troubleshooting workflows.

PowerMTA.in Editorial · Technical guide · Updated 2026
Read the guide →
$ dig TXT powermta.in +short
;; ANSWER SECTION
"v=spf1 include:_spf.powermta.in ~all"
;; query time: 11 msec — status: NOERROR
Advertisement

Latest technical guides

Practical guides for people building and operating email systems.

View all →
Advertisement

Explore by topic

Go directly to the part of email infrastructure you need.

SMTP

Gmail Sender Requirements: SPF, DKIM, DMARC, TLS and Unsubscribe ExplainedGuide
SMTP TLS Explained: STARTTLS, Implicit TLS and Certificate TroubleshootingGuide
SMTP 550 Error: Meaning, Causes and How to Diagnose a RejectionGuide
SMTP vs Email API: Which Sending Method Should Your Application Use?Guide

DNS

PTR and Reverse DNS for Email Servers: A Practical Configuration GuideGuide
MX Records for Email: How Mail Routing Works and How to Troubleshoot ItGuide
Email DNS Records Explained: A, AAAA, MX, TXT, CNAME and MoreGuide
MX Record vs A Record for Email: The Difference ExplainedGuide

Authentication

Free SPF Record GeneratorGuide
Free DMARC Record GeneratorGuide
Free DKIM GeneratorGuide
DMARC Monitoring Guide: From p=none to Enforcement Without Breaking MailGuide

Deliverability

Email Deliverability Checklist — Complete Inbox Placement Guide for Indian SendersGuide
Email Bounce Handling: Hard vs Soft Bounces and What to Do With ThemGuide
Hard Bounce vs Soft Bounce: What They Mean and How to Handle ThemGuide
Domain Warm-Up vs IP Warm-Up: What Is the Difference?Guide

Infrastructure

How to Install Acelle Mail on Docker: Complete GuideGuide
How to Install Acelle Mail on cPanel: Complete GuideGuide
How to Install Sendy on Docker: Complete GuideGuide
How to Install MailWizz on Docker: Complete GuideGuide

Email Infrastructure

Mailchimp vs Brevo — Which Is Better for Indian Businesses in 2026?Guide
How to Write Email Subject Lines That Get Opened — 20 Proven TipsGuide
How to Choose the Perfect Email Sender Name — Complete Guide for 2026Guide
Free UTM Campaign BuilderGuide

Free email tools

Use a tool, then follow the related guide to understand the result.

All tools →
Spf GeneratorFree utilityDmarc GeneratorFree utilityDkim GeneratorFree utilitySubject Line GeneratorFree utilityEmail Header AnalyzerFree utilityEmail Id GeneratorFree utilitySubject Line TesterFree utilityUnsubscribe Footer GeneratorFree utilityBimi Record GeneratorFree utilityAmazon Commission CalculatorFree utility
Advertisement

A technical publication, not a generic blog.

PowerMTA.in focuses on SMTP, DNS, authentication, deliverability and email infrastructure.

Editorial policy →