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Email Deliverability (Email Deliverability)

Security Glossary - Email Authentication

Definition: Email deliverability is the ability of your emails to successfully reach recipients' inboxes rather than being rejected, bounced, or filtered to spam. It depends on technical factors (SPF, DKIM, DMARC, reverse DNS), sender reputation (domain and IP), content quality, and recipient engagement.

The Importance of Email Deliverability

Poor email deliverability means your transactional emails (password resets, order confirmations, notifications) may not reach users, and your marketing emails get filtered to spam. This directly affects user experience, customer trust, and business revenue.

Technical email authentication is the foundation of deliverability. Without properly configured SPF, DKIM, and DMARC, many email providers will filter your messages to spam regardless of content quality. Google and Yahoo implemented new sender requirements in 2024 that mandate authentication for bulk senders.

Beyond authentication, deliverability depends on IP and domain reputation. Sending from an IP address previously used for spam, having high bounce rates, or sending to many invalid addresses all damage reputation. Monitoring bounce rates, spam complaints, and DMARC reports helps maintain good deliverability.

Checking Your Setup

A DNS health checker verifies the technical foundations of deliverability: SPF, DKIM, DMARC, reverse DNS, and MX records. For deeper deliverability monitoring, also check your domain and IP reputation with tools that track blacklists, bounce rates, and spam complaint rates.

See how your site handles Email Deliverability

Check DNS Health

Email Deliverability FAQ

Why are my emails going to spam?
Common causes: missing or misconfigured SPF/DKIM/DMARC, poor sender reputation (new IP, shared with spammers), missing reverse DNS, high bounce rates, or content that triggers spam filters. Check authentication first, then reputation, then content.
What are the minimum requirements for email deliverability?
At minimum: a valid SPF record authorizing your sending servers, DKIM signing with proper alignment, a DMARC record (even p=none), reverse DNS on your sending IP, and valid MX records. Google and Yahoo also require one-click unsubscribe for marketing emails.

Related Concepts

Sender Policy Framework DomainKeys Identified Mail Domain-based Message Authentication, Reporting and Conformance Reverse DNS Domain Blacklist Check
Disclaimer: DomainOptic provides automated informational scans only. Results do not constitute professional security advice, compliance certification, or a guarantee of security. Always verify findings independently.