Blog
Guides, tutorials, and engineering notes from Reloop Labs on email infrastructure, deliverability, self-hosting, and transactional email.
The Hidden Costs of Disposable Emails (And How Blocking Them Saves You Thousands)
From CRM contact-tier inflation to free-trial credit farming and burned domain reputation, here is the real cost of disposable emails and how a free temp email checker saves thousands.
How to Block Disposable Emails at Signup (Free Temp Email Checker)
Stop throwaway signups before they bounce, burn free trials, and tank sender reputation. Use Reloop's free temp email checker: ~210k disposable domains, no SMTP probing.
Building in Public: Lessons From Growing Reloop
What we've learned building Reloop in public, from the first commit to shipping real features, growing the community, and staying focused.
Why We Open-Sourced Our Email Infrastructure
The story behind Reloop: why we built an open-source alternative to SendGrid, Resend, and Mailgun, why email infrastructure is too critical to rent forever, and what we're changing.
Send Email from Cloudflare Workers
Send transactional email from Cloudflare Workers using Reloop's HTTP API, with no Node.js SDK required. Works on the edge runtime.
Email with SvelteKit: A Developer's Guide
Send transactional email from SvelteKit server endpoints and form actions using Reloop's Node.js SDK, with full TypeScript support.
Send Transactional Email from Remix
Add reliable transactional email to your Remix app using Reloop's Node.js SDK, from loader/action setup to environment variable handling.
BIMI: Show Your Logo in the Gmail Inbox
BIMI (Brand Indicators for Message Identification) lets verified senders display their logo next to emails in Gmail and Apple Mail. Here's how to set it up.
IP Warming Schedule Guide: How to Build Sender Reputation (2026)
A comprehensive, practical guide to warming new sending IP addresses, with an exact week-by-week volume ramp schedule, recipient segmentation strategy, throttle limits, and deliverability monitoring.
Why Your Emails Land In Spam & How to Fix It
The definitive guide to diagnosing and fixing email spam folder placement, covering authentication, content, reputation, list hygiene, and ISP-specific issues.
Reloop on Coolify: Self-Hosted Email Without the Complexity
Deploy Reloop using Coolify's UI-driven deployment, no Docker expertise required. Full email infrastructure in under 20 minutes.
How to Check if an Email is Disposable (Free Temp Email Checker)
In this guide, you'll learn what disposable emails are, why they matter, and how you can quickly check if an email is disposable.
Reloop on Fly.io: Full Deployment Guide
Deploy Reloop on Fly.io, from fly launch to a production-ready email infrastructure with persistent volumes and custom domains.
Self-Host Your Email Infrastructure for $5/Month
A complete guide to running your own transactional email stack with Reloop on a cheap VPS (SMTP, REST API, analytics dashboard, and bounce handling) for less than a cup of coffee a month.
Introducing Reloop: Open-Source Email Infrastructure Developers Actually Want to Use
Open-source email infrastructure for indie hackers, startups, product teams, and enterprises. Ship transactional mail, agent inboxes, and inbound on Reloop Cloud or self-host: same product, no lock-in.
Welcome Email Sequences That Actually Convert
The anatomy of a high-converting SaaS welcome email sequence, from the first send to the first meaningful action.
How to Use Email to Reduce Churn: Sequences That Work
A practical breakdown of the email sequences that reduce SaaS churn, from early warning signals to win-back campaigns.
Transactional Email as a Growth Channel (Not Just Notifications)
Most teams treat transactional email as infrastructure. The best SaaS companies use it as a retention and expansion channel. Here's how.
Vercel AI SDK + Reloop: Send Smart Notifications from Your AI App
Combine the Vercel AI SDK's tool calling with Reloop to trigger intelligent, context-aware email notifications from any AI-powered Next.js application.
How to Use AI to Generate Transactional Email Templates
Use LLMs to generate, personalize, and iterate on transactional email templates, then send them reliably with Reloop.
Build an AI Agent That Sends Emails on Your Behalf
Learn how to build an autonomous AI agent that composes and sends emails using tool calling, with Reloop handling delivery.
How We Handle Email Bounce Processing Automatically
Inside Reloop's bounce processing pipeline: classifying hard vs soft bounces, updating suppression lists, and protecting sender reputation automatically.
I Let an AI Agent Read and Reply to My Emails. Here's How the Infrastructure Works.
Building an AI agent that reads and replies to email is easy in LangChain. Owning the send-and-receive layer is the hard part, and why open-source email infrastructure matters.
Building a Webhook Delivery System That Actually Retries
How Reloop built a reliable, observable webhook delivery system with exponential backoff, signature verification, and replay support.
How We Built a Multi-Tenant Email Delivery Queue with BullMQ
A deep dive into the job queue architecture powering Reloop's multi-tenant email delivery: rate limiting, priority lanes, and failure recovery.
SPF, DKIM, and DMARC: The Complete Setup Guide (2026)
A thorough, practical guide to configuring SPF, DKIM, and DMARC for your sending domain with exact DNS records, common mistakes, and a step-by-step verification checklist.
Migrating from SendGrid to Reloop
Step-by-step migration: map APIs, switch SMTP, update webhooks, and validate deliverability during the cutover.
Transactional Email Best Practices: The Complete Developer Guide
Everything you need to send fast, reliable, inbox-landing transactional email, from domain setup and template design to delivery patterns and monitoring.
How to Send Email in Next.js App Router (2026)
Send transactional email from Next.js App Router with Reloop: complete Server Action and Route Handler examples, env setup, error handling, and Vercel deploy.
Self-Hosted Email Infrastructure: When and How
Why teams self-host email, what Reloop gives you out of the box, and how to deploy with Docker Compose.
Email Provider Comparison: Resend vs SendGrid vs Reloop
A 2026 comparison of developer email providers on open source, self-hosting, campaigns, and pricing.
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