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Posts by: Amar

Amar CP is the Co-Founder and Sales Director at Mailercloud, where he leads partnerships, alliances, and customer growth. With over a decade of experience in application development, database architecture, and scaling web systems, Amar brings a rare blend of engineering depth and go-to-market expertise to email marketing. He writes about email deliverability, marketing automation, and helping small businesses grow smarter with data-driven campaigns.

Spamhaus Delisting: How to Fix SBL and CSS Listings (2026)

Amar

Spamhaus Delisting: How to Fix SBL and CSS Listings (2026)

Your campaign goes out, and within minutes your bounce log fills with something like this: 550

Barracuda Blocklist Removal: Fix BRBL Blocks (2026 Guide)

Amar

Barracuda Blocklist Removal: Fix BRBL Blocks (2026 Guide)

Your campaign goes out, and a slice of it comes straight back: 554 Service unavailable; Client

Emails Going to Spam Only at Outlook? A Diagnostic Guide

Amar

Emails Going to Spam Only at Outlook? A Diagnostic Guide

This is the pattern, and if you're here you already recognize it: Gmail open rate 34%. Yahoo fi

Gmail & Yahoo Sender Requirements: The Complete 2026 Reference

Amar

Gmail & Yahoo Sender Requirements: The Complete 2026 Reference

Last reviewed: 10 August 2026 Any domain sending close to 5,000 or more messages a day to person

550 5.7.1 Outlook: Why Microsoft Is Blocking Your Email

Amar

550 5.7.1 Outlook: Why Microsoft Is Blocking Your Email

Your campaign goes out, and Outlook and Hotmail addresses start bouncing with something like this:

Mimecast Blocked Email? Why It Rejects You and How to Fix It

Amar

Mimecast Blocked Email? Why It Rejects You and How to Fix It

You send a campaign to a list of corporate contacts, and a slice of it comes back looking like this

Blocked by Proofpoint? How to Fix Proofpoint Email Blocks (2026 Guide)

Amar

Blocked by Proofpoint? How to Fix Proofpoint Email Blocks (2026 Guide)

You launch a campaign, and suddenly a chunk of your emails bounce back with a message like this:

SMTP 5.7.x Bounce Codes Decoded: 5.7.1 and the Policy Family

Amar

SMTP 5.7.x Bounce Codes Decoded: 5.7.1 and the Policy Family

A message leaves your queue, gets accepted at the TCP level, negotiates TLS, sends its recipients,

UCEPROTECT Delisting: Do Level 2 and 3 Listings Matter?

Amar

UCEPROTECT Delisting: Do Level 2 and 3 Listings Matter?

You run a blocklist check on your sending IP, and a monitoring tool lights up red: Your IP 203.

How to Set Up SPF, DKIM & DMARC: Implementation Guide

Amar

How to Set Up SPF, DKIM & DMARC: Implementation Guide

Email authentication stopped being optional in February 2024, when Google began enforcing requireme

Microsoft Sender Requirements: The Complete 2026 Reference

Amar

Microsoft Sender Requirements: The Complete 2026 Reference

If you send more than 5,000 messages a day to Outlook.com, Hotmail, Live or MSN addresses from a si

Gmail 421 4.7.0 and 4.7.28 Deferrals: What They Mean and How to Fix

Amar

Gmail 421 4.7.0 and 4.7.28 Deferrals: What They Mean and How to Fix

Your queue starts backing up, delivery slows to a crawl, and your logs fill with lines like this:

12 Best GetResponse Alternatives in 2026 (Free & Paid)

Amar

12 Best GetResponse Alternatives in 2026 (Free & Paid)

In January 2025, GetResponse quietly restructured its pricing and introduced peak-subscriber billin