> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mailofly.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Overview of sending domains, authentication, and DNS verification in Mailofly.

# Domains Introduction

Adding and verifying a custom domain is essential for sending authenticated, high-deliverability emails with Mailofly.

## Why Verify a Domain?

Unverified sender addresses are rejected by major mailbox providers (Gmail, Outlook, Yahoo) to prevent phishing and spoofing. Adding your domain configures:

* **DKIM (DomainKeys Identified Mail)**: Cryptographically signs your emails to prove they originated from your domain and were not tampered with in transit.
* **SPF (Sender Policy Framework)**: Authorizes Mailofly's IP addresses to dispatch emails on behalf of your domain.
* **DMARC (Domain-based Message Authentication)**: Specifies policies for how mailbox providers should handle unauthenticated emails.

## Supported Domain Types

You can add both root/apex domains (e.g. `example.com`) or subdomains (e.g. `mail.example.com`, `notifications.example.com`). We recommend dedicated subdomains for separation of transactional and marketing traffic.


## Related topics

- [Introduction](/introduction.md)