How to Reduce SPAM and Improve Email Deliverability
SPAM is a common issue affecting email communication. These are unsolicited messages often blocked or filtered by mail servers. In this guide, you'll learn how to increase the deliverability of legitimate emails and reduce the chances of ending up in the spam folder.
Check your mail server status
Make sure your mail server is not listed on public blacklists. You can use free online tools to verify this. If the server is blacklisted, contact your provider’s support team. For shared hosting, the provider will typically handle the delisting.
Use an SSL certificate for mail servers
Ensure your server uses secure SSL/TLS connections and SMTP authentication. These settings are generally enabled by default in most hosting environments. Refer to your provider’s documentation for setup instructions.
Check if your domain is blacklisted
Your domain name can also be blacklisted, especially if previously linked to spam activity. Use the same blacklist checker used for servers. If listed, you must request removal yourself through the listing service.
Correctly configure DNS records
Certain DNS records help email providers verify the sender's identity and improve delivery reputation:
- SPF: defines which servers are authorized to send emails on behalf of your domain.
- DKIM: adds a digital signature to validate message integrity.
- DMARC: enforces SPF and DKIM policies and provides reporting (optional but recommended).
If you're using your provider's nameservers, SPF and DKIM may already be configured. Always verify their presence and correctness.
Watch your email content
Email filters analyze content to determine spam likelihood. Here are some tips to avoid being flagged:
- Suspicious keywords: avoid aggressive marketing or sensitive terms (e.g., "amazing offer", "sex", "drugs").
- External links: use only trusted domains and limit the number of URLs. Avoid public URL shorteners.
- Attachments: when possible, upload the file to your server and share the link instead of attaching files directly.
- Unsubscribe link: mandatory for newsletters or recurring emails.
Manage your domain reputation
Your domain's reputation is affected by spam complaints, sending frequency, and bounce rates. Avoid mass unsolicited sends, honor unsubscribe requests, and monitor delivery errors.
Warning
Even with all best practices in place, email deliverability is never guaranteed. Receiving servers use different and often dynamic spam filtering rules that may still flag your messages.
