feat(PROJ-89): BCC auslesen, indexieren, in Sichtbarkeitsprüfung und Portal anzeigen

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

pkg/mailparser/bcc.go

@@ -0,0 +1,30 @@
+package mailparser
+
+import (
+	"net/mail"
+	"strings"
+)
+
+func bccAddresses(header string) []string {
+	if strings.TrimSpace(header) == "" {
+		return nil
+	}
+	addrs, err := mail.ParseAddressList(header)
+	if err != nil {
+		return nil
+	}
+	var out []string
+	seen := make(map[string]struct{})
+	for _, a := range addrs {
+		addr := strings.ToLower(strings.TrimSpace(a.Address))
+		if addr == "" {
+			continue
+		}
+		if _, dup := seen[addr]; dup {
+			continue
+		}
+		seen[addr] = struct{}{}
+		out = append(out, addr)
+	}
+	return out
+}

pkg/mailparser/bcc_test.go

@@ -0,0 +1,61 @@
+package mailparser_test
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestBCCAddresses(t *testing.T) {
+	tests := []struct {
+		name    string
+		headers string
+		want    []string
+	}{
+		{
+			name:    "missing",
+			headers: "",
+			want:    nil,
+		},
+		{
+			name:    "single",
+			headers: "Bcc: alice@example.com\r\n",
+			want:    []string{"alice@example.com"},
+		},
+		{
+			name:    "multiple with display names, lowercased and deduplicated",
+			headers: "Bcc: Alice <Alice@Example.com>, bob@example.com, ALICE@example.com\r\n",
+			want:    []string{"alice@example.com", "bob@example.com"},
+		},
+		{
+			name:    "unparseable yields nothing",
+			headers: "Bcc: not an address <<<\r\n",
+			want:    nil,
+		},
+		{
+			name:    "empty header",
+			headers: "Bcc: \r\n",
+			want:    nil,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			pm := parseHeaders(t, tt.headers)
+			if !reflect.DeepEqual(pm.BCC, tt.want) {
+				t.Errorf("BCC = %#v, want %#v", pm.BCC, tt.want)
+			}
+		})
+	}
+}
+
+func TestBCCDoesNotAffectToCC(t *testing.T) {
+	pm := parseHeaders(t, "Cc: erin@example.com\r\nBcc: frank@example.com\r\n")
+	if !reflect.DeepEqual(pm.To, []string{"dave@example.org"}) {
+		t.Errorf("To = %#v", pm.To)
+	}
+	if !reflect.DeepEqual(pm.CC, []string{"erin@example.com"}) {
+		t.Errorf("CC = %#v", pm.CC)
+	}
+	if !reflect.DeepEqual(pm.BCC, []string{"frank@example.com"}) {
+		t.Errorf("BCC = %#v", pm.BCC)
+	}
+}

pkg/mailparser/parser.go

@@ -28,6 +28,7 @@ type ParsedMail struct {
 	From        string
 	To          []string
 	CC          []string
+	BCC         []string
 	Subject     string
 	MessageID   string
 	InReplyTo   string   // In-Reply-To header (single message-id, no angle brackets)
@@ -167,6 +168,8 @@ func Parse(raw []byte) (pmOut *ParsedMail, errOut error) {
 		}
 	}
 
+	pm.BCC = bccAddresses(msg.Header.Get("Bcc"))
+
 	pm.DeliveryAddresses = deliveryAddresses(msg.Header)
 
 	// Subject - decode MIME encoded-words