# DNS Crash Course for Founders & Clients

**Category:** Technical Guides  
**Date:** Jan 27, 2026  
**Author:** Keyona Meeks  
**Read Time:** 12 min  
**URL:** https://rerev.io/blog/dns-crash-course-for-founders-and-clients

A practical, orientation-first guide to understanding DNS without breaking your website, email, or apps.

## How to Use This Guide

Most founders only touch DNS when something breaks or when a tool tells them: "Add this DNS record." This guide exists to make DNS predictable instead of scary.

- Read Sections 1–3 once to understand the mental model
- Bookmark Sections 5, 8, and 9 for real-world setup moments
- Use Section 10 anytime you are launching, migrating, or integrating tools

## 1. What DNS Is and Why It Always Matters

DNS (Domain Name System) is the system that tells the internet what to do when someone uses your domain name. It translates `yourdomain.com` into instructions for where your website lives, where your email should go, and which services are allowed to act on your behalf.

## 2. The Mental Model: DNS as Your Business Routing System

Think of DNS as your business routing system, not a website setting. DNS connects your website host, email provider, apps and services, and analytics and security tools.

Key insight: Your website host is not your DNS host. Your email provider is separate again. DNS is the only place where your website, email, and apps intersect.

## 3. DNS Record Types

- **A Record:** Points your domain to an IP address (your website)
- **CNAME:** Creates an alias pointing to another domain
- **MX Records:** Routes email to the correct mail server
- **TXT Records:** Used for verification and security (SPF, DKIM, DMARC)
- **NS Records:** Specifies which nameservers control your DNS

## 4. How DNS Propagation Works

DNS changes aren't instant. Changes propagate across global DNS servers over 1–48 hours (usually 1–4 hours). During this time, some users may see old settings while others see new ones.

## 5. Setting Up Website DNS

1. Get your hosting provider's IP address or CNAME target
2. Create an A record (or CNAME) pointing your domain to your host
3. Add a www CNAME pointing to your root domain
4. Wait for propagation

## 6. Setting Up Email DNS

1. Add MX records from your email provider
2. Add SPF TXT record to authorize sending servers
3. Add DKIM TXT record for email authentication
4. Add DMARC TXT record for email security policy

## 7. Common DNS Mistakes

- Changing nameservers when you only needed to add a record
- Deleting existing records when adding new ones
- Not waiting for propagation before troubleshooting
- Confusing your registrar, DNS host, and web host

## When You Will Actually Touch DNS

- Launching a website
- Switching hosts or platforms
- Setting up custom-domain email
- Adding services like Mailgun, Stripe, Webflow, Shopify
- Migrating servers or apps

---

*Published by ReRev Labs — https://rerev.io*