Merajul Haque
Full-Stack Developer
Outreach Automation / AI SaaS
Cold Mailer Case Study & Specifications
Write Once. Reach Many.
coldmailer.site
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Outreach Automation / AI SaaS2026
Cold Mailer
Write Once. Reach Many.
Find the right companies, personalize your outreach, and manage cold email campaigns with your own sending infrastructure.
Project Specifications
Category:
Outreach Automation / AI SaaS
Year / Release:
2026
Deployment Status:
Active / Production
License / Code:
Proprietary / On Request
Industry:
Career Technology, Sales & Productivity
Frontend Framework:
Next.js 16 (React 19, TypeScript)
Styling & UI Primitives:
Tailwind CSS 4 & Radix UI
Database & ODM:
MongoDB with Mongoose 9
Email Infrastructure:
BYOK SMTP via Nodemailer
Email Verification:
Verifalia Integration
Authentication & Security:
jose (JWT) & Security Hardening
AI Architecture:
Provider-Oriented with Metering & Quotas
Deployment & Analytics:
Vercel Analytics & Production Deployment
Data Processing:
Papaparse (CSV Import/Export)
“Write once. Reach many.”
About the Project
Cold Mailer is a privacy-first cold outreach and AI email platform designed to help job seekers, developers, and professionals discover relevant companies and manage personalized email outreach from one workspace. The platform combines a curated directory of 10,000+ startups, SaaS, and AI companies with an email composer, AI-assisted pitch generation, contact discovery, email verification via Verifalia, sending configuration, and outreach tracking. Its Bring Your Own Key (BYOK) approach supports user-controlled email infrastructure via personal SMTP transports, while its AI capabilities include provider integration, usage metering, quotas, credit-based management, and end-to-end security hardening.
Key Features & Engineering Highlights
Curated Company Directory — Searchable database of 10,000+ startups, SaaS, and AI companies categorized by location and hiring status
Skill-Based Company Search — Filter company records by technology tags including React, Next.js, MERN, AI, and Node
Personalized Markdown Email Composer — Dedicated workspace for drafting, formatting, previewing, and organizing targeted cold outreach
AI Pitch Generation — Context-aware AI pitch creation tailored to specific job opportunities, portfolios, and company requirements
Bring Your Own Key (BYOK) SMTP — User-controlled email delivery allowing direct connection to personal SMTP sending infrastructure
Email Verification Integration — Integrated Verifalia validation pipeline ensuring deliverability before campaign dispatch
Resume & Profile Workspace — Built-in resume management, customized attachments, profile records, and outreach preferences
Outreach Tracking & Analytics — Real-time analytics, sent/unsent status monitoring, and campaign history logs
AI Usage Metering & Quota Engine — Multi-provider AI architecture with automated usage metering, credit management, and quota enforcement
Automated Test Coverage — Comprehensive test suites covering AI generation, payment plans, BYOK administration, and security hardening
System Architecture
High-Level Architecture Pipeline
User Input → Provider & Access Resolution → AI Pitch Generation → Quota & Usage Validation → BYOK SMTP Dispatch
BYOK SMTP Infrastructure
User-controlled email dispatch connecting to personal SMTP servers without proprietary vendor lock-in
AI Generation & Metering Engine
Modular provider integration with credit management, rate limiting, and quota enforcement
Verifalia Email Verification
Pre-dispatch inbox verification reducing bounce rates and protecting domain reputation
MongoDB & Mongoose Persistence
Schema-backed storage for company directory, resumes, outreach history, and account settings
Papaparse CSV Processing
High-performance CSV parsing and data transformation for lead lists and contact records
Vercel Analytics & jose Auth
Lightweight cryptographic session tokens and real-time user engagement analytics
Technologies & Architecture
Core frameworks, runtime technologies, databases, and UI libraries employed in this project.
Next.js 16React 19TypeScriptTailwind CSS 4MongoDBMongooseNodemailerVerifaliaCloudinaryZodRadix UIPapaparse
Frontend Technologies
Next.js 16App Router framework and full-stack application routing
React 19Modern component-based user interfaces and server components
TypeScriptEnd-to-end static typing across frontend and server handlers
Tailwind CSS 4Modern utility-first styling with responsive design tokens
Radix UIUnstyled accessible UI primitives and modals
Lucide ReactClean, scalable interface iconography
Vercel AnalyticsPrivacy-focused website and outreach telemetry
Backend & Integrations
MongoDB & Mongoose 9Document database and schema object modeling layer
NodemailerConfigurable transport for BYOK SMTP email sending
VerifaliaAutomated email address validation service integration
joseLightweight JWT signing and cryptographic operations
CloudinaryCloud media storage for resume documents and brand assets
Zod 4Runtime data validation and environment variable schemas
PapaparseIn-browser and server-side CSV data parsing
tsxTypeScript execution for migration scripts and test runners
Experience Cold Mailer Live
Explore the responsive interface, live workflows, and interact with the production deployment.
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