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Guides

Guides to warmup, cold email and deliverability.

Long-form guides from the Warmerly team. Start with the overview chapter in each guide, or search for the question you have today.

Guides
Chapters
12 chapters

Email warmup guide

How warmup works, how long it takes, and how to do it on Gmail, Google Workspace and Outlook.

Start with the overview →11 chapters

Email outreach guide

Templates, sequences, subject lines, personalisation, sending limits and the stack behind cold email that gets replies.

Start with the overview →10 sections, one page

Cold email deliverability guide

SPF, DKIM, DMARC, domain warmup, sending volume, list hygiene and spam complaints, on one long page.

Read the guide →
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Choose the closest one. You get the chapters in the order we would read them.

12 chapters

Email warmup guide

How warmup works, how long it takes, and how to do it on Gmail, Google Workspace and Outlook.

Start with the overview

Start here

  1. What Is Email Warmup? How It Works, How Long It Takes, and How to Do ItWhat email warmup is, the signals Gmail and Outlook score, how the warmup ramp works, and step-by-step guides for Gmail, Outlook and new domains.Overview

Set it up on your mailbox

  1. How to Warm Up a New Email Domain Without Getting FlaggedWarm up a new email domain without getting flagged: the authentication checklist, Warmerly's 30-day ramp, and why jumping straight to high volume hurts.
  2. Gmail Email Warmup: How to Warm Up Gmail Mailboxes for Cold OutreachGmail email warmup for cold outreach: the signals Gmail tracks, why reputation drops in 24 to 48 hours but recovers in weeks, and how to know you're ready.
  3. Google Workspace Email Warmup: How to Do It Right Before Cold OutreachGoogle Workspace email warmup before cold outreach: 2048-bit DKIM, SPF and DMARC setup, the 30-day ramp, common mistakes, and how to know you're ready.
  4. Outlook Email Warmup: How to Warm Up Microsoft 365 and Outlook.com MailboxesOutlook email warmup for Microsoft 365 and Outlook.com mailboxes: the EOP signals, 2048-bit DKIM, SNDS setup, Warmerly's 30-day ramp and placement checks.
  5. The Honest Math of Email Warmup: How Long Should It Actually Take?How long email warmup takes: Warmerly's 30-day ramp from 4 to 50 messages a day, what changes it, and the signs a mailbox is ready.

Do it well

  1. Email Warmup Best Practices: How to Do It Right in 2026Email warmup best practices for 2026: 2048-bit DKIM, sensible schedules, tool selection, warmup alongside campaigns, and the signs you can scale.

Choose a tool

  1. 14 Best Email Warmup Tools in 2026 (Real Pricing Compared)Best email warmup tools in 2026 for Gmail and Outlook: Warmerly, Instantly, Smartlead, Mailreach, Lemwarm and Warmup Inbox, with pricing compared.
  2. Free Email Warmup Tools in 2026: Which Ones Have a Genuinely Free PlanFree email warmup tools in 2026: the 4 with a genuinely free plan, their exact limits, Gmail and Outlook support, and which free trials need no card.
  3. Email Warmup Pricing Comparison 2026: What 13 Tools Cost for 1, 5 and 25 MailboxesEmail warmup pricing compared for 2026: Warmup Inbox, TrulyInbox, Mailwarm, Mailreach, Lemwarm, Instantly, Smartlead and more at 1, 5 and 25 mailboxes.
  4. Email Warmup Tools for Agencies (2026): Unlimited Mailboxes and Pricing ComparedEmail warmup tools for agencies in 2026: Instantly, Smartlead, Warmy, TrulyInbox, MailReach and Warmerly on unlimited mailboxes, clients and pricing.
  5. Email Warmup Tools for Gmail and Outlook (2026): Pricing and How Each ConnectsEmail warmup tools for Gmail, Outlook and Microsoft 365 in 2026: Warmup Inbox, TrulyInbox, MailReach, Lemwarm and more, by price and how each connects.
11 chapters

Email outreach guide

Templates, sequences, subject lines, personalisation, sending limits and the stack behind cold email that gets replies.

Start with the overview

Start here

  1. Email Outreach: The Complete Guide for 2026Email outreach is emailing prospects who haven't asked to hear from you. How it works: lists, subject lines, sequences, deliverability. Free plan.Overview

Write the emails

  1. Cold Email Templates That Get Replies in 2026Cold email outreach templates for B2B sales, first touch, follow-up, and break-up emails, with notes on personalisation and why short emails win.
  2. Cold Email Subject Lines That Get OpenedWhat makes a cold email subject line get opened, length, tone, personalisation, and the words to avoid. With examples and a note on spam triggers.
  3. Email Personalisation at Scale Without Sounding Like a RobotEmail personalisation at scale, by the mechanics: variables vs. research, signal sources, fallback logic, and how to keep relevance high.
  4. Email Outreach Sequences: Structure, Timing, and CadenceHow to build an email outreach sequence, how many emails, how to space them, what each touch should say, and when to stop. With a sample cadence.

Get them delivered

  1. Email Outreach Deliverability: How to Reach the InboxWhy outreach emails go to spam and how to fix it, authentication, warmup, list hygiene, and sending reputation. The layer every campaign needs.
  2. How Many Cold Emails Can You Send Per Day? Safe Limits for 2026How many cold emails per mailbox per day in 2026: Gmail, Google Workspace and Microsoft 365 sending limits, the safe cold email number and how to ramp.
  3. Email Outreach Automation: What to Automate (and What to Never Touch)Email outreach automation done right: what to automate, what stays manual, and how to scale sends without wrecking deliverability or sounding like a bot.

Plan and measure

  1. B2B Email Outreach: A Playbook That Books MeetingsHow B2B email outreach works in 2026, targeting the buying committee, writing cold emails that earn replies, and the deliverability that gets them seen.
  2. Cold Email Reply Rate Benchmarks: What's Normal and How to Beat ItCold email reply rate benchmarks by segment, the formula that defines a reply, and the levers that move you from a 1% trickle to a healthy 5 to 10% range.
  3. Email Outreach Tools: How to Build Your StackThe three layers of an email outreach stack (finding contacts, sending and sequencing, and warmup/deliverability) and how to choose tools for each.
One page, 10 sections

Cold email deliverability guide

SPF, DKIM, DMARC, domain warmup, sending volume, list hygiene and spam complaints, on one long page.

Read the full guide
  1. What deliverability actually means
  2. The 2026 baseline: SPF, DKIM, DMARC, and MTA-STS
  3. Why domain warmup matters more than IP warmup
  4. The signals Gmail's neural classifier actually weights
  5. The Microsoft SmartScreen reality
  6. List hygiene, bounces, and the 2% complaint trap
  7. Content patterns to avoid (and which 'rules' are myths)
  8. Cadence: how often to send, when to send, and when to stop
  9. The cold-email-specific stack we recommend
  10. What to do when reputation drops
Glossary

Every term that matters, in plain English.

 Blog

Deliverability, warmup, written by people who ship it.

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