---
title: "The State of Cold Email: Free Deliverability Newsletter"
description: "Placement data, provider rule changes and new deliverability research from a team sending a million cold emails a month. Free, unsubscribe any time."
url: https://warminboxes.com/state-of-cold-email
breadcrumb: "Home > Deliverability Hub > State of Cold Email"
---
Newsletter

# The State of Cold Email

What is actually landing in the inbox, from a team sending a million cold emails a month. Placement data, provider changes and new research, written by operators. Free.

First nameWork emailSubscribe free

No spam, unsubscribe any time. See our [privacy policy](https://warminboxes.com/privacy).

## In each issue

- What our placement tests measuredThe latest results from the inbox placement log we publish whole, bad months included.
- What the providers changedGoogle, Microsoft and Yahoo sender rules, and what each change means for a cold email setup.
- New studies and playbooksResearch measured on live sending infrastructure, and the operator guides that came out of it.
- New free toolsCheckers, planners and MCP tools as they ship, with what each one can and cannot see.

From the Deliverability Hub

## Everything we know about getting cold email delivered

[3 playbooks

### Deliverability Playbooks

Cold email operator strategies we run at Upscale B2B, our own agency, sending a million emails a month. Written from running them, not from reading about them.

See the playbooks](https://warminboxes.com/playbooks)[3 studies

### Deliverability Studies

Original research measured on live sending infrastructure rather than surveyed. Every figure comes from our own fleet or a full sweep of real domains, bad months included.

See the studies](https://warminboxes.com/research)

### Read now

- [Placement · 6 min readEvery placement test we ran on prewarmed inboxesEvery new batch of prewarmed inboxes is seed-tested before it ships, and only stock clearing 95% is deployed. 8 tests, 469,331 messages scored, published whole — a live read on how hard inboxing got through 2026. Every results screen is on the page.](https://warminboxes.com/research/inbox-placement-log)
- [Domains · 11 min readA study of top-level domains by sends3,415,449 sends split across five TLDs and scored against Google’s permanent domain-reputation verdict. .link drew it 16 times more often than .com, and .org twice as often — and the gap holds inside a single client, where the copy and the list are the same. The TLD you buy predicts this better than anything else we measured, and unlike a blocklist listing it costs replies.](https://warminboxes.com/research/google-sender-reputation)
- [Blocklists · 10 min readDoes a SURBL listing actually hurt cold email? We tested 2,817 sending domainsA DNS sweep of every live sending domain, not a sample. 43.3% were listed, and reply rate barely moved: 1.14% to 1.16%. Includes the three mechanisms we diagnosed SURBL grouping domains on — shared keyword, redirects to one master, shared nameserver zones — and the fix for each.](https://warminboxes.com/research/surbl-blocklist-study)
- [Inboxing · 25 min readThe 2026 Inboxing PlaybookA clean operator guide for building cold email infrastructure that survives longer, routes smarter, and keeps campaigns out of spam.](https://warminboxes.com/inboxing-playbook)
- [Personalization · 12 min readThe Ultimate Liquid Syntax Guide: Hidden Ways To Personalize Cold Emails Using Your SequencerHow to make cold emails feel timely, human, and relevant at scale with Liquid syntax, smarter conditional logic, and better sending context.](https://warminboxes.com/playbooks/liquid-syntax-guide)
- [Deliverability · 18 min readHow to Avoid the SPAM Plague in 2026: The Complete List Verification, ESP, ESG & Role Segmentation PlaybookA field-tested cold email segmentation system for cleaner lists, better inbox routing, sharper persona-based copy, and higher reply rates before you ever launch.](https://warminboxes.com/playbooks/spam-plague-segmentation-playbook)

[Open the Deliverability Hub](https://warminboxes.com/deliverability-hub)[Free deliverability tools](https://warminboxes.com/deliverability-tools)