Deliverability Insights
Deep analysis of email authentication and spam scores
Deliverability Insights
InboxIssue provides detailed analysis of your email deliverability, including authentication results, spam scores, and reputation data.
Authentication Analysis
SPF (Sender Policy Framework)
SPF verifies that the sending server is authorized to send email for your domain.
| Result | Meaning | Impact |
|---|---|---|
| pass | IP authorized | Positive |
| fail | IP not authorized | Negative (spam) |
| softfail | IP probably not authorized | Slight negative |
| neutral | No assertion | Neutral |
| none | No SPF record | Negative |
DKIM (DomainKeys Identified Mail)
DKIM adds a cryptographic signature to verify email authenticity.
| Result | Meaning | Impact |
|---|---|---|
| pass | Signature valid | Positive |
| fail | Signature invalid | Negative (spam) |
| none | No signature | Slight negative |
DMARC (Domain-based Message Authentication)
DMARC combines SPF and DKIM with policy instructions.
| Policy | Meaning |
|---|---|
| none | Report only, don't reject |
| quarantine | Send failures to spam |
| reject | Block unauthenticated emails |
| Result | Meaning |
|---|---|
| pass | Aligned with policy |
| fail | Failed alignment |
Microsoft Spam Analysis
For Microsoft mailboxes (Outlook.com, Office 365), InboxIssue extracts detailed spam scores.
SCL (Spam Confidence Level)
| Score | Interpretation | Typical Outcome |
|---|---|---|
| -1 | Safe sender bypass | Inbox |
| 0-1 | Very low spam probability | Inbox |
| 2-4 | Low spam probability | Inbox |
| 5-6 | Medium spam probability | Spam folder |
| 7-8 | High spam probability | Spam folder |
| 9 | Very high spam probability | Blocked |
BCL (Bulk Complaint Level)
Measures if your email appears to be bulk/marketing mail.
| Score | Interpretation |
|---|---|
| 0 | Not bulk mail |
| 1-3 | Low bulk characteristics |
| 4-7 | Medium bulk characteristics |
| 8-9 | High bulk characteristics |
Composite Authentication (CompAuth)
Microsoft's combined authentication verdict:
| Code | Meaning |
|---|---|
| 0 | Explicit authentication failure |
| 1-99 | Implicit authentication failure |
| 100-199 | Authentication passed |
| 200-299 | Soft-passed implicit auth |
| 300-399 | Not checked |
| 400-499 | Bypassed checking |
PCL (Phishing Confidence Level)
| Value | Meaning |
|---|---|
| 0 | Not phishing |
| 1-3 | Low phishing probability |
| 4-8 | High phishing probability |
Header Analysis
InboxIssue parses email headers for detailed insights:
Routing Information
- Sending IP address
- HELO/EHLO domain
- Relay path
Authentication Headers
- Authentication-Results
- ARC (Authenticated Received Chain)
- DKIM-Signature
Provider-Specific Headers
- X-MS-Exchange-* (Microsoft)
- X-Gm-* (Gmail)
- X-Yahoo-* (Yahoo)
IP Reputation
InboxIssue checks sender IP reputation:
Blacklist Status
- Spamhaus
- Barracuda
- Spamcop
- Others
Reputation Indicators
- PTR record (reverse DNS)
- IP age and history
- Sending volume patterns
Recommendations
Based on analysis, InboxIssue provides actionable recommendations:
Authentication Issues
- "Add SPF record for sending domain"
- "Enable DKIM signing"
- "Publish DMARC policy"
Content Issues
- "Reduce spam trigger words"
- "Improve text-to-image ratio"
- "Add unsubscribe link"
Reputation Issues
- "Check blacklist status"
- "Review sending volume"
- "Warm up new IPs"
Related
- Understanding Results - Result interpretation
- Spam Tests - Running tests
- Subscription Plans - Feature access