98% Deliverability: What It Really Takes and How to Achieve It

In today’s crowded inboxes, achieving high email deliverability is the difference between your cold outreach being seen or being lost in the void. For startups and sales teams, hitting the elusive 98% deliverability mark isn’t just a vanity metric; it’s the foundation for successful campaigns, stronger pipelines, and real business growth. But what does it actually take to reach and sustain such a high standard?
This guide unpacks the technical, tactical, and strategic steps required to consistently land your cold emails in the inbox. Drawing on proven practices and Mailpool’s own expertise (98% deliverability, 100x scaling, and 10-minute onboarding), you’ll get a practical roadmap to optimize your sending practices, protect your sender reputation, and maximize ROI.

Understanding Email Deliverability

What Is Email Deliverability?

Email deliverability is the ability of your messages to reach recipients’ inboxes, rather than being filtered to spam or bouncing entirely. It’s not just about whether your email is sent, it’s about whether it’s actually seen and read by the intended audience.

Inbox Placement vs. Delivery

It’s common to confuse delivery (the message leaves your outbox) with deliverability (the message lands in the inbox). True success means your emails are placed in the primary inbox, not the spam or promotions tab.

Common Myths and Misconceptions

• Myth: High sending volume guarantees inbox placement.
• Fact: Quality and reputation matter more than sheer volume.
• Myth: Good content alone is enough.
• Fact: Technical setup and sender reputation are equally critical.

Core Factors That Affect Deliverability

Sender Reputation

Your sender reputation is like a credit score for your email domain and IP address. ISPs and spam filters assess past behavior, bounces, complaints, and engagement rates to decide if your emails are trustworthy.

Technical Setup (SPF, DKIM, DMARC, DNS)

Proper configuration of DNS records and authentication protocols is non-negotiable. SPF, DKIM, and DMARC prove you are who you say you are, reducing the risk of spoofing and boosting trust with ISPs.

List Quality and Hygiene

Sending to outdated, purchased, or unverified lists leads to bounces and spam complaints. Clean, engaged lists are the backbone of deliverability.

Sending Practices (Volume, Frequency, Warm-Up)

Sudden spikes in volume or erratic sending patterns are red flags for ISPs. Gradual warm-up, consistent schedules, and respecting daily limits (e.g., 20–100 emails/inbox/day) are essential.

Content and Personalization

Generic, spammy, or overly promotional content triggers filters. Personalized, relevant messages perform better for both deliverability and engagement.

Engagement Metrics

High open, reply, and click rates signal to ISPs that your emails are wanted. Low engagement or high spam complaints hurt your reputation.

Achieving 98% Deliverability: Step-by-Step Guide

Technical Setup for Success

DNS Configuration, SPF, DKIM, and DMARC

The foundation of high deliverability is a robust technical setup. Proper DNS records and authentication protocols (SPF, DKIM, DMARC) are essential. These records tell receiving servers that your emails are legitimate, dramatically reducing the chances of being flagged as spam or phishing.

• SPF (Sender Policy Framework): Confirms which mail servers are allowed to send on behalf of your domain.
• DKIM (DomainKeys Identified Mail): Adds a digital signature to emails, verifying they haven’t been altered in transit.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): Sets policies for handling unauthenticated emails and provides reporting.

Mailpool automates much of this process, making setup fast and foolproof, even for non-technical users.

Dedicated vs. Shared IPs

Dedicated IPs offer more control but require careful warm-up and consistent sending volume. Shared IPs are easier to manage for smaller senders, but they mean your reputation is pooled with others. 

Setting Up New Domains and Inboxes

• Use new domains for cold outreach to protect your main brand domain.
• Limit new inboxes to 3–5 per domain.
• Follow a gradual warm-up: start with 20 emails/day, increasing to 100 over several weeks.

Building and Maintaining Sender Reputation

Warm-Up Strategies

Start slow. Gradually increase sending volume over 3–4 weeks. 

Consistent Sending Volumes

Avoid erratic spikes. ISPs favor predictable, steady sending patterns. Schedule campaigns to align with your historical patterns.

Avoiding Spam Traps and Blacklists

• Never buy lists.
• Validate emails before sending.
• Monitor blacklists and use feedback loops to resolve issues quickly.

Monitoring Reputation

There are tools and dashboards that help you track sender reputation, bounce rates, and spam complaints in real time. Take action at the first sign of trouble.

List Building & Hygiene

Sourcing Quality Leads

• Use opt-in forms, LinkedIn, and reputable databases.
• Avoid scraping or buying lists.

Regular Cleaning and Validation

• Remove bounced or unengaged addresses regularly.
• Use validation tools to check for typos and inactive domains.

Opt-In and Permission Best Practices

• Always get explicit or implied consent.
• Make it easy for people to unsubscribe.

Sending Practices That Work

Volume Recommendations and Scheduling

To maintain high deliverability, stick to recommended sending volumes: start with 20 emails per inbox per day and gradually scale up to a maximum of 100 per day. For each domain, keep inboxes to 3–5. Consistency is key, avoid sudden spikes or drops in volume. Use tools to schedule emails at natural intervals rather than sending in large bursts.

Personalization and Content Best Practices

Personalized messages not only increase engagement but also improve deliverability. Avoid spammy words and phrases (“free,” “guaranteed,” “act now”), excessive punctuation, or all-caps subject lines. Keep content relevant, concise, and focused on providing value to the recipient. A/B test subject lines and body copy to discover what resonates best with your audience.

A/B Testing and Optimization

Test different subject lines, opening sentences, calls to action, and even sending times. Track open rates, reply rates, and click-throughs to identify patterns. Use these insights to refine your approach and maximize both deliverability and campaign effectiveness.

Monitoring and Troubleshooting

Tracking Inbox Placement Rates

Monitor not only delivery rates but also where your emails are landing, in the inbox, promotions, or spam. Mailpool provides insights into placement rates across major providers like Gmail, Outlook, and Yahoo.

Analyzing Bounce and Spam Rates

High bounce or spam complaint rates are red flags. Regularly review your metrics, remove problematic addresses, and adjust your sending practices if you notice negative trends.

Tools for Monitoring

Leverage dashboards and alerts to stay on top of deliverability health. Mailpool and other platforms offer real-time reporting, so you can act quickly if issues arise.

What to Do When Deliverability Drops

If you see a dip in inbox placement:

• Pause sending to problem lists
• Re-validate your list
• Review your technical setup
• Warm up your domains again if needed
• Seek expert help if issues persist

Common Pitfalls and How to Avoid Them

Over-Sending

Sending too many emails too quickly is one of the fastest ways to damage your sender reputation and trigger spam filters. Stick to gradual increases in volume and always follow recommended daily limits.

Poor Technical Setup

Incorrect or missing SPF, DKIM, or DMARC records, or misconfigured DNS, can get your emails blocked or marked as suspicious. Use automated tools (like Mailpool) to double-check your setup.

Ignoring Engagement Signals

Low open, reply, or click rates and high spam complaints signal to ISPs that your emails are unwanted. Continuously monitor engagement and trim inactive recipients from your lists.

Neglecting List Hygiene

Failing to clean your list regularly leads to high bounce rates and more spam complaints. Make list validation and cleaning a regular part of your process.

Conclusion

Achieving 98% email deliverability is both a science and an art. It requires the right technical setup, disciplined sending practices, and a commitment to ongoing monitoring and optimization. By following these best practices and leveraging tools like Mailpool you can ensure your cold emails consistently land in the inbox, driving growth for your startup or sales team.
Ready to see 98% deliverability in action? Book a demo with Mailpool and start maximizing your outreach today.