Warmbly

The largest open-source B2B cold outreach and email warmup service.

Digital Marketing & SEOGoApache-2.0

Abstract

Warmbly is an open-source Digital Marketing & SEO project. The largest open-source B2B cold outreach and email warmup service. ⭐ Help us reach more senders and grow the Warmbly community. Star this repo! It is built using Go. Key capabilities include: Campaigns - multi-step sequences with per-mailbox caps and spacing; Unified inbox - every mailbox and reply in one place; CRM - contacts, pipelines, deals, tasks, meetings. The complete source code is publicly available on GitHub under the Apache License 2.0, making it a useful reference for students building a Digital Marketing & SEO mini project or final-year project.

1. Introduction

⭐ Help us reach more senders and grow the Warmbly community. Star this repo!

Warmbly runs cold email campaigns from the mailboxes you already own and warms them so they keep landing in the inbox. Opens, clicks, and replies land in a shared dashboard the moment they happen, and it's AI-native, so your team and its agents work in it together, live.

Warmbly splits into a control plane (backend API, consumer, Postgres, Redis, and the event bus) that owns all state, and an execution plane of interchangeable Go workers that send and sync mail. Workers never touch Postgres, and outbound mail leaves through each mailbox's own provider, not the worker's IP, so you add throughput by running more workers.

2. Objective

The largest open-source B2B cold outreach and email warmup service.

This project demonstrates how Go can be applied to a real-world Digital Marketing & SEO problem.

3. Key Features / Modules

  • Campaigns - multi-step sequences with per-mailbox caps and spacing
  • Unified inbox - every mailbox and reply in one place
  • CRM - contacts, pipelines, deals, tasks, meetings
  • Warmup - a pool of monitored mailboxes, not throwaway accounts
  • Deliverability - bounces, complaints, suppression, inbox placement
  • Automations - visual reply playbooks with AI steps
  • Integrations - HubSpot, Slack, Zapier, REST API, webhooks
  • Realtime - live presence and edits across your team

4. Technology Stack

Go

5. System Requirements

General requirements for this technology stack — check the README for exact versions.

  • Go 1.20 or later
  • Git (to clone the repository)

6. Installation & Setup

git clone https://github.com/warmbly/warmbly.git
cd warmbly
git clone https://github.com/warmbly/warmbly && cd warmbly
make dev

Full setup instructions are in the project README.

7. Future Enhancements

Suggested extensions you can add to make this your own project.

  • Export reports to Google Sheets or PDF
  • Schedule weekly automated reports
  • Add competitor comparison

8. Viva / Review Questions

Common questions examiners ask for projects in this domain.

  1. Which marketing or SEO problem does this tool solve?
  2. Which data sources or APIs does it use (Search Console, Analytics, social platforms)?
  3. Which metrics or KPIs does it report and how are they calculated?
  4. How could the output help a business make decisions?
  5. How would you schedule it to run automatically?

9. Source Code & License

This project is developed by warmbly and published on GitHub under the Apache License 2.0. Please follow the license terms and credit the original author when you use or modify this code.

View Source on GitHubDownload ZIP

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