How to improve my email deliverability ?

What is email deliverability?

Email deliverability is the ability of your messages to reach recipients’ inboxes instead of being filtered as spam or rejected by mail servers. It depends on technical configuration, sender reputation, contact-list quality and relevant content. This guide covers practical steps to improve deliverability and maintain a healthy sender reputation.

1. Configure domain authentication

Domain authentication helps receiving servers verify that mail is authorized by your domain and detect forged messages.

Required DNS records:

• SPF (Sender Policy Framework): Specifies which servers may send mail using your domain in the envelope sender address.

• DKIM: (DomainKeys Identified Mail) adds a cryptographic signature so recipients can verify the signed content and signing domain.

• DMARC: (Domain-based Message Authentication, Reporting & Conformance) specifies a policy for messages that fail DMARC. Passing requires either SPF or DKIM to pass and align with the visible From domain.

Add these records to the authoritative DNS configuration for your domain. Then verify them using DNS checks or your mail provider’s authentication tools. You can also review records through Email Deliverability in cPanel. See this guide: How to use Email Deliverability in cPanel

2. Build a stable sender reputation

Providers such as Gmail and Outlook consider your sending domain and IP reputation. A healthy reputation develops over time through legitimate, reliable sending.

Good practices:

• Start with small volumes and increase gradually.

• Avoid large sending bursts from new domains or IP addresses.

• Initially send only to active, engaged contacts who have agreed to receive your messages.

• Keep a consistent sending pattern instead of abrupt changes.

Stable, expected sending can support your reputation and inbox placement, but does not guarantee delivery.

3. Maintain a healthy contact list

A clean, active contact list helps deliverability. Obsolete or invalid addresses create bounces and can damage your domain’s reputation.

Good practices:

• Use double opt-in with a confirmation email for new subscriptions.

• Never buy email lists; they often include invalid addresses or people who did not consent.

• Regularly remove or suppress:

  • Addresses producing hard bounces (permanent delivery errors);

  • Contacts inactive for several months, according to your re-engagement policy;

  • People who unsubscribed or reported your mail as spam.

• Segment contacts by engagement and adjust sending frequency for each group.

• Maintain a suppression list for invalid, permanently bounced and unsubscribed addresses, and apply it to future sends.

Good list hygiene reduces bounces and spam complaints, supporting deliverability.

4. Create relevant, appropriate email content

Design and content affect recipient trust and how messages are evaluated. Follow good practices for every message.

Recommendations:

• Use clear subjects that accurately describe the message. Avoid misleading offers, excessive capitals and punctuation; no single word automatically determines spam placement.

• Make messages readable with useful text and appropriate images. Do not rely on an arbitrary text-to-image ratio as a guarantee of inbox placement.

• Use trustworthy, verified links. Avoid broken or misleading links.

• Include a visible, working unsubscribe link in subscription and marketing messages.

• Use a recognizable sender name and address, such as YourCompany and support@example.com.

• Personalize content where appropriate to make it relevant and encourage useful engagement.

5. Monitor performance and sender reputation

Monitor delivery indicators to identify and address problems promptly.

Key indicators:

• Open rate: Can indicate recipient interest, but privacy features and automated fetching affect its accuracy.

• Click-through rate (CTR): Helps measure engagement with links in the message.

• Bounce rate: Keep it low and investigate increases; 2% is a common operational benchmark, not a universal provider rule.

• Spam complaint rate: Aim to remain below 0.1% and follow the receiving provider’s requirements

• Unsubscribe rate: A high rate may indicate irrelevant content or excessive sending frequency.

Useful tools:

• Google Postmaster Tools : Check available domain reputation data and delivery errors.

• Sender Score or Microsoft SNDS: Review available IP reputation information.

• Blocklist checkers: Check whether your domain or IP appears on relevant blocklists.

If indicators do not improve, reduce campaign volume, review list quality and correct your sending practices.

6. Control sending frequency and volume

Large or erratic volumes can harm reputation or trigger restrictions. Keep sending consistent and appropriate for your recipients.

Good practices:

• Increase volume gradually.

• Avoid large campaigns to inactive or unengaged contacts.

• Respect account limits and do not send uncontrolled bulk mail.

• For substantial campaigns, use a suitable service with volume management, unsubscribe tools and reporting.

• Send in planned batches rather than abrupt bursts.

Conclusion: Improving deliverability combines technical configuration, consistent sending and relevant content. Authenticate your domain, maintain a healthy contact list, offer clear unsubscribe options and monitor results. These practices support sender reputation and delivery, without guaranteeing placement in every recipient’s inbox.