---
title: "Deliverability Starts Before DMARC: Use Verified Contact Data and Custom Domains | DMARC Report"
description: "In 2025, email deliverability has become even more complex. Big email providers like Gmail and Microsoft have changed the rules for who can reach the inbox."
image: "https://dmarcreport.com/og/blog/deliverability-before-dmarc-verified-contact-data-custom-domains-guide.png"
canonical: "https://dmarcreport.com/blog/deliverability-before-dmarc-verified-contact-data-custom-domains-guide/"
---

Quick Answer

In 2025, email deliverability has become even more complex. Big email providers like Gmail and Microsoft have changed the rules for who can reach the inbox. Although \[DMARC\](https://dmarcreport.com/), SPF, and DKIM setups are essential to email deliverability, these three on their own may still not be enough. The foundation of success relies on two essentials: verified contact data and custom domains.

Related: [Free DMARC Checker](/tools/dmarc-checker/) ·[How to Create an SPF Record](/tools/spf-record-generator/) ·[SPF Record Format](/blog/spf-format-checker-dos-and-donts-for-email-authentication/) 

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![Deliverability Starts Before DMARC: Use Verified Contact Data and Custom Domains](https://media.mailhop.org/dmarcreport/images/2022/04/dmarc-alignment-6379.jpg) 

## Try Our Free DMARC Checker

Validate your DMARC policy, check alignment settings, and verify reporting configuration.

[ Check DMARC Record → ](/tools/dmarc-checker/) 

DMARC ([RFC 7489](https://datatracker.ietf.org/doc/html/rfc7489)) ties SPF and DKIM together by requiring alignment between the envelope sender and the visible `From` header. According to Google’s February 2024 bulk sender requirements, a DMARC policy of at least `p=none` is now mandatory for any domain sending 5,000+ messages per day to Gmail users.

> Email deliverability starts with authentication, says Brad Slavin, General Manager of DuoCircle. In 2026, if your SPF, DKIM, and DMARC aren’t all passing and aligned, your email goes to spam. It’s not about content anymore - receivers check authentication before they even look at what you wrote.

Email authentication directly impacts deliverability: Google and Yahoo’s February 2024 bulk sender requirements enforce SPF + DKIM + DMARC as hard prerequisites for inbox placement. Unauthenticated bulk mail is now routed to spam or rejected outright by both providers. In 2025, email deliverability has become even more complex. Big email providers like \*\*Gmail and Microsoft \*\*have changed the rules for who can reach the inbox. Although [DMARC](https://dmarcreport.com/), SPF, and DKIM setups are essential to email deliverability, these three on their own may still not be enough. The foundation of success relies on two essentials: verified contact data and custom domains.

## Why DMARC Alone Won’t Fix Your Email Problems

DMARC verifies that e-mails are sent from **legitimate senders**, but fails to address the problem of sending to invalid addresses. You are left with incorrect or outdated addresses on your list, resulting in high bounce rates. Email providers closely monitor [bounce rates](https://www.optimizely.com/optimization-glossary/bounce-rate/) and may label you as sub-prime, even with a pristine DMARC setup.

## The Real Cost of Invalid Email Addresses

![Dmarc check](https://media.mailhop.org/dmarcreport/images/2025/10/dmarc-check-8877.jpg) 

_Each time you email an address that does not exist, email providers log the attempt_. High bounce rates basically indicate to providers that you’re not doing a good job of keeping your lists clean. A sender with a bounce rate of 10% or higher is considered risky, affecting all future email sends.

Many email platforms will bill you according to either the \*\*number of contacts or the number of emails sent. Holding onto bad addresses also translates into paying for contacts who will never get your content. Bad data also wastes your team’s time chasing nonexistent contacts.

## How Verified Contact Data Improves Deliverability

A good bounce rate occurs when you start with verified and accurate email addresses, which reduces hard bounces. Email providers consider this one way to confirm you’re not a spammer. \*\*Good verification ensures that addresses are live, mail servers are ready, and those mailboxes have not been marked as spam traps.

Tools that provide verified contact data have become essential for B2B outreach. For example, [SignalHire is a modern hiring extension](https://www.signalhire.com/extension) that offers verified emails and phone numbers through browser tools that work directly with LinkedIn and other professional networks. These tools help teams find accurate contact info without manual research that often leads to outdated data.

![Dmarc record](https://media.mailhop.org/dmarcreport/images/2025/10/dmarc-record-1178.jpg) 

## Why Custom Domains Matter for Deliverability

_When you send from yourcompany.com rather than on Gmail or Yahoo, you are the custodian of your reputation_. Shared spaces have the reputation that everyone wears them. If another user spams, they can affect us all on that domain. With a custom domain, you \*\*establish a reputation based on whatever you do.

With custom domains, you have full control over how authentication occurs. You can configure [SPF](https://dmarcreport.com/what-is-spf/), DKIM, and DMARC correctly, which can’t be done with shared domains.

## How Do You Configure Up Your Custom Domain?

Setting up your custom domain for email requires **several technical steps**. Here’s the basic setup:

**SPF Records**: Inform email servers which \*\*IP addresses are authorized to send email from your domain. An SPF record looks like this: v=spf1 include:spf.google.com \~all

![What is dmarc](https://media.mailhop.org/dmarcreport/images/2025/10/what-is-dmarc-3622.jpg) 

**DKIM**: Adds a digital signature to your emails. Most email platforms generate [DKIM keys](https://dmarcreport.com/blog/dkim-key-rotation-best-practices-for-large-organizations-should-know/) for you and tell you exactly how to add them to your DNS .

**DMARC**: Start with a monitoring policy: v=DMARC1; p=none; rua=mailto:[dmarc@yourdomain.com](mailto:dmarc@yourdomain.com). This tells servers to monitor failures and send you reports. Later, you can **switch to stricter policies**.

## Key Metrics to Track for Email Deliverability

Understanding which numbers matter helps you catch problems early. Here’s a breakdown of the most important metrics:

\*\*MetricWhat It MeasuresHealthy TargetWarning Sign Hard Bounce Rate

Emails to invalid addresses

Below 2%

Above 5%

Spam Complaint Rate

Recipients marking as spam

Below 0.1%

Above 0.3%

Inbox Placement Rate

Emails reaching primary inbox

Above 95%

Below 85%

Open Rate

Recipients opening emails

15-25%

Below 10%

Authentication Pass Rate

SPF/DKIM passing

Above 99%

Below 95%

These metrics reveal different aspects of your email health. Bounce rates show data quality. Complaint rates indicate whether people want to receive your emails. Engagement rates affect your long-term reputation\*\*.

![Dmar record generator](https://media.mailhop.org/dmarcreport/images/2025/10/dmar-record-generator-8841.jpg) 

## What Are Best Practices for Maintaining Email Deliverability?

_Maintaining strong deliverability isn’t a one-and-done so far as setup is concerned_. It needs constant vigilance and intelligent \*\*behaviour that safeguards your sender reputation in the long run.

Keep a Close Eye on Your Metrics: Watch your bounce rates, spam complaints, and engagement stats for all the campaigns you send. Observe trends and patterns within your data. Dramatic, sudden changes typically indicate that something’s wrong, whether it be a technical issue or a content problem caused by an objectively measurable decline in the \*\*quality of backlinks to your lists. Establish automated alerts to enable you to detect and correct problems quickly before they tarnish your reputation. The sooner you identify problems, the easier they are to fix.

Keep Authentication Current: Whenever you migrate your email to a new platform or add new sending infrastructure, update your SPF, DKIM, and [DMARC records](https://dmarcreport.com/dmarc-record/) immediately. Stale authentication records can prevent valid emails from authenticating, resulting in a negative impact on deliverability. _Check your DNS quarterly to ensure all is accurate and working as intended_. This regular housecleaning prevents authentication failures, which could cause your emails to be sent to spam.

![Dmarc report](https://media.mailhop.org/dmarcreport/images/2025/10/dmarc-report-5552.jpg) 

_Gradually Increase Volume: If you intend to send larger volumes than usual, we recommend gradually increasing your volume over several weeks_. You want to get the system going smoothly, a kind of like stretching before a workout; you don’t want to shock the system. Spike in volume overnight? alert [spam filters](https://www.fortinet.com/uk/resources/cyberglossary/spam-filters) and make \*\*email providers wonder what happened with your sending habits. Incremental increases signal to providers that your growth is both organic and legitimate, allowing you to maintain good inbox delivery as you expand.

Be Consistent: Send emails frequently and predictably so that email clients perceive you as a trusted sender. Outreach, whether daily, weekly, or monthly, sending at a steady cadence establishes trust with inbox providers. One such behavior - going silent for months and then suddenly sending thousands of emails - will set off spam filters even if you have great real-time authentication\*\*. Set a schedule and keep it.

## Finding Quality Contact Data

How you get contact data directly affects deliverability and results.

## Best Sources for Contact Data:

- **Website Forms**: People who sign up through your website are the highest quality contacts\*\* - **Professional Networking Platforms**: LinkedIn helps you find decision-makers, like searching[ through Google employees list](https://www.signalhire.com/companies/google/employees) to identify prospects
- **Contact Discovery Tools**: These tools find and verify professional information from multiple sources
- **Data Enrichment**: Fill in missing details in your existing database
![Dmarc analyzer](https://media.mailhop.org/dmarcreport/images/2025/10/dmarc-analyzer-7794.jpg) 

## How Do You Avoid These:?

- **Purchased Lists**: Generate high bounces and [spam complaints](https://www.scworld.com/news/ftc-lodges-new-set-of-complaints-against-alleged-cell-phone-spammers)
- **Unverified Scraped Data**: Creates the same problems as purchased lists

## Essential List Hygiene Practices

Even confirmed contacts go bad after a while. Research indicates that 22-30% of email addresses degrade each year.

Key practices:

- Standard Confirmation: Review your list **every 3-6 months**.
- Purge Hard Bounces: Any hard bounces need to be purged as soon as possible
- Handle Inactivity Contacts: Delete contacts who have not opened an email in 6+ months
- Run a Re-engagement Campaign: Attempt to warm up “cold” contacts before flushing them out.
- Enable Easy Unsubscribing: Simple unsubscribing options will lower your complaints from spam

## Building Verification Into Your Workflow

Current verification tools can integrate with APIs to verify addresses at the point of entry. If you have access to contact discovery applications, platforms such as \*\*SignalHire verify the information \*\*upon discovery, meaning addresses are already verified by the time they reach your outreach lists. Batch verification can also be useful prior to running large campaigns.

![Gmail dmarc](https://media.mailhop.org/dmarcreport/images/2025/10/gmail-dmarc-5609.jpg) 

## Conclusion: Build Strong Foundations for Email Success

_It takes more than DMARC and other authentication protocols to ensure successful email delivery_. It’s built on top of predictable contact data, and correctly set up for your custom domains. One bounces and hits [spam traps](https://www.darkreading.com/physical-security/spam-emails-bring-bomb-threats-to-us-businesses-schools), omitting any email addresses that could do so. By using custom domains, you can establish and manage your own online reputation.

By starting with a \*\*strong foundation of trust around vetted data, combined with custom domains, before you even implement your authentication protocols, you are setting yourself up for sustainable and secure operations. _The basics remain the same: Send to people who want to hear from you, use infrastructure under your control, authenticate your messages, and continually monitor and well-test_.

## Topics

[ dkim ](/tags/dkim/)[ DMARC ](/tags/dmarc/)[ dmarc record ](/tags/dmarc-record/)[ SPF ](/tags/spf/) 

![Vishal Lamba](https://media.mailhop.org/dmarcreport/images/team/vishal-lamba.jpg) 

[ Vishal Lamba ](/authors/vishal-lamba/) 

Content Specialist

Content Specialist at DMARC Report. Writes vendor-specific email authentication guides and troubleshooting walkthroughs.

[LinkedIn Profile →](https://www.linkedin.com/in/vishal-lamba/) 

## Take control of your DMARC reports

Turn raw XML into actionable dashboards. Start free - no credit card required.

[Start Free Trial](https://app.dmarcreport.com/) [Check Your DMARC Record](/tools/dmarc-checker/) 

## Related Articles

[  Foundational 7m  4 sectors that need email authentication the most and why  Oct 15, 2024 ](/blog/4-sectors-that-need-email-authentication-the-most-and-why/)[  Foundational 4m  8 Misconceptions About DMARC and its Deployment for Businesses  Dec 4, 2023 ](/blog/8-misconceptions-about-dmarc-and-its-deployment-for-businesses/)[  Foundational 8m  9 technologies to protect your emails from cyber actors  Dec 10, 2024 ](/blog/9-technologies-to-protect-your-emails-from-cyber-actors/)[  Foundational 14m  Add TXT Record on Namecheap (SPF, DKIM & DMARC) - 2026  Mar 5, 2025 ](/blog/add-txt-record-on-namecheap-a-complete-dns-guide/)

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