analyzer: correct auth scoring weights, x-aligned-from penalty, and RBL divide-by-zero

pkg/analyzer/authentication.go

@@ -174,9 +174,7 @@ func (a *AuthenticationAnalyzer) CalculateAuthenticationScore(results *model.Aut
 	score += 12 * a.calculateXGoogleDKIMScore(results) / 100
 
 	// Penalty-only: X-Aligned-From (up to -5 points on failure)
-	if xAlignedScore := a.calculateXAlignedFromScore(results); xAlignedScore < 100 {
-		score += 5 * (xAlignedScore - 100) / 100
-	}
+	score += 5 * a.calculateXAlignedFromScore(results) / 100
 
 	// Ensure score doesn't exceed 100
 	if score > 100 {

pkg/analyzer/authentication_test.go

@@ -47,7 +47,7 @@ func TestGetAuthenticationScore(t *testing.T) {
 					Result: model.AuthResultResultPass,
 				},
 			},
-			expectedScore: 73, // SPF=25 + DKIM=23 + DMARC=25
+			expectedScore: 90, // SPF=30 + DKIM=30 + DMARC=30
 		},
 		{
 			name: "SPF and DKIM only",
@@ -59,7 +59,7 @@ func TestGetAuthenticationScore(t *testing.T) {
 					{Result: model.AuthResultResultPass},
 				},
 			},
-			expectedScore: 48, // SPF=25 + DKIM=23
+			expectedScore: 60, // SPF=30 + DKIM=30
 		},
 		{
 			name: "SPF fail, DKIM pass",
@@ -71,7 +71,7 @@ func TestGetAuthenticationScore(t *testing.T) {
 					{Result: model.AuthResultResultPass},
 				},
 			},
-			expectedScore: 23, // SPF=0 + DKIM=23
+			expectedScore: 30, // SPF=0 + DKIM=30
 		},
 		{
 			name: "SPF softfail",
@@ -80,7 +80,7 @@ func TestGetAuthenticationScore(t *testing.T) {
 					Result: model.AuthResultResultSoftfail,
 				},
 			},
-			expectedScore: 4,
+			expectedScore: 5, // 30 * 17 / 100 = 5
 		},
 		{
 			name:          "No authentication",
@@ -97,7 +97,7 @@ func TestGetAuthenticationScore(t *testing.T) {
 					Result: model.AuthResultResultPass,
 				},
 			},
-			expectedScore: 35, // SPF (25) + BIMI (10)
+			expectedScore: 40, // SPF (30) + BIMI (10)
 		},
 	}
 

pkg/analyzer/authentication_x_aligned_from.go

@@ -51,16 +51,16 @@ func (a *AuthenticationAnalyzer) calculateXAlignedFromScore(results *model.Authe
 	if results.XAlignedFrom != nil {
 		switch results.XAlignedFrom.Result {
 		case model.AuthResultResultPass:
-			// pass: positive contribution
-			return 100
+			// pass: no impact
+			return 0
 		case model.AuthResultResultFail:
 			// fail: negative contribution
-			return 0
+			return -100
 		default:
 			// neutral, none, etc.: no impact
 			return 0
 		}
 	}
 
-	return 100
+	return 0
 }

pkg/analyzer/authentication_x_aligned_from_test.go

@@ -92,18 +92,18 @@ func TestCalculateXAlignedFromScore(t *testing.T) {
 		expectedScore int
 	}{
 		{
-			name: "pass result gives positive score",
+			name: "pass result gives no penalty",
 			result: &model.AuthResult{
 				Result: model.AuthResultResultPass,
 			},
-			expectedScore: 100,
+			expectedScore: 0,
 		},
 		{
-			name: "fail result gives zero score",
+			name: "fail result gives full penalty",
 			result: &model.AuthResult{
 				Result: model.AuthResultResultFail,
 			},
-			expectedScore: 0,
+			expectedScore: -100,
 		},
 		{
 			name: "neutral result gives zero score",

pkg/analyzer/rbl.go

@@ -318,7 +318,7 @@ func (r *DNSListChecker) CalculateScore(results *DNSListResults, forWhitelist bo
 		return 100, ""
 	}
 
-	if results.ListedCount <= 0 {
+	if results.ListedCount <= 0 || scoringListCount <= 0 {
 		return 100, "A+"
 	}