diff --git a/internal/ai_client/client.go b/internal/ai_client/client.go
index c395f06..1a8b589 100644
--- a/internal/ai_client/client.go
+++ b/internal/ai_client/client.go
@@ -73,7 +73,7 @@ func (d *Dispatcher) Dispatch(task *database.Task) {
 		SessionID:   task.ThreadID,
 		History:     history,
 		CallbackURL: callbackURL,
-		Metadata:    map[string]string{"task_uuid": task.TaskUUID},
+		Metadata:    buildDispatchMetadata(task),
 	}
 
 	// Update status to AI_PROCESSING before first attempt.
@@ -195,3 +195,18 @@ func (d *Dispatcher) buildHistory(threadID string) ([]historyEntry, error) {
 
 	return history, nil
 }
+
+// buildDispatchMetadata constructs the metadata map for OpenClaw dispatch,
+// merging the task UUID with any DispatchContext from the rules pipeline.
+func buildDispatchMetadata(task *database.Task) map[string]string {
+	metadata := map[string]string{"task_uuid": task.TaskUUID}
+	if task.DispatchContext != "" {
+		var ctx map[string]string
+		if err := json.Unmarshal([]byte(task.DispatchContext), &ctx); err == nil {
+			for k, v := range ctx {
+				metadata[k] = v
+			}
+		}
+	}
+	return metadata
+}
diff --git a/internal/config/config.go b/internal/config/config.go
index 13e8d1d..e0adcb0 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -31,6 +31,7 @@ type Config struct {
 	BridgeCallbackToken string
 	SystemEmail         string
 	WhitelistEmails     []string
+	BlocklistEmails     []string
 
 	// Optional
 	IMAPProxyURL string
@@ -74,6 +75,14 @@ func Load() (*Config, error) {
 		}
 	}
 
+	if raw := os.Getenv("BLOCKLIST_EMAILS"); raw != "" {
+		for _, email := range strings.Split(raw, ",") {
+			if trimmed := strings.TrimSpace(email); trimmed != "" {
+				cfg.BlocklistEmails = append(cfg.BlocklistEmails, trimmed)
+			}
+		}
+	}
+
 	if cfg.ListenAddr == "" {
 		cfg.ListenAddr = ":8080"
 	}
diff --git a/internal/database/models.go b/internal/database/models.go
index f779396..a1cbac0 100644
--- a/internal/database/models.go
+++ b/internal/database/models.go
@@ -24,6 +24,7 @@ type Task struct {
 	Sender          string
 	Subject         string
 	BodyPlain       string
+	DispatchContext string // JSON metadata from external rules pipeline.
 	AIResponse      string
 	Status          string `gorm:"index;not null"`
 	AttemptOpenClaw int    `gorm:"default:0"`
diff --git a/internal/mail/imap.go b/internal/mail/imap.go
index 6fe6f32..da22273 100644
--- a/internal/mail/imap.go
+++ b/internal/mail/imap.go
@@ -3,6 +3,7 @@ package mail
 import (
 	"context"
 	"crypto/tls"
+	"encoding/json"
 	"fmt"
 	"io"
 	"log/slog"
@@ -21,6 +22,7 @@ import (
 	"thuanle.me/claw-email-bridge/internal/config"
 	"thuanle.me/claw-email-bridge/internal/database"
 	"thuanle.me/claw-email-bridge/internal/logging"
+	"thuanle.me/claw-email-bridge/internal/rules"
 )
 
 // IMAPWatcher monitors an IMAP mailbox via IDLE and processes new emails.
@@ -32,6 +34,8 @@ type IMAPWatcher struct {
 	dialIMAP         func(addr string, options *imapclient.Options) (*imapclient.Client, error)
 	dialIMAPViaProxy func(addr, proxyURL string, options *imapclient.Options) (*imapclient.Client, error)
 
+	rules *rules.Pipeline
+
 	// onReceived is called after a task is saved as RECEIVED.
 	// This will be wired to the OpenClaw dispatch in a future step.
 	OnReceived func(task *database.Task)
@@ -57,11 +61,20 @@ var socks5DialerFactory = proxy.SOCKS5
 
 // NewIMAPWatcher creates a new IMAP watcher.
 func NewIMAPWatcher(cfg *config.Config, db *gorm.DB) *IMAPWatcher {
+	var externalRules []rules.Rule
+	if len(cfg.WhitelistEmails) > 0 {
+		externalRules = append(externalRules, rules.NewWhitelistRule(cfg.WhitelistEmails))
+	}
+	if len(cfg.BlocklistEmails) > 0 {
+		externalRules = append(externalRules, rules.NewBlocklistRule(cfg.BlocklistEmails))
+	}
+
 	return &IMAPWatcher{
 		cfg:              cfg,
 		db:               db,
 		dialIMAP:         imapclient.DialTLS,
 		dialIMAPViaProxy: dialTLSViaSOCKS5,
+		rules:            rules.NewPipeline(externalRules),
 	}
 }
 
@@ -343,10 +356,15 @@ func (w *IMAPWatcher) processMessage(c *imapclient.Client, buf *imapclient.Fetch
 		return
 	}
 
-	// 2. Whitelist: skip if sender not in allowed list.
-	if !w.isWhitelisted(sender) {
-		log.Info("imap: sender not whitelisted, ignoring", "sender", sender)
-		w.saveIgnored(messageID, sender, subject, "not whitelisted")
+	// 2. External rules: evaluate operator-configurable policy.
+	ruleResult := w.rules.Evaluate(rules.EmailContext{
+		Sender:    sender,
+		Subject:   subject,
+		MessageID: messageID,
+	})
+	if !ruleResult.Accepted {
+		log.Info("imap: rejected by external rules", "sender", sender, "reason", ruleResult.Reason)
+		w.saveIgnored(messageID, sender, subject, ruleResult.Reason)
 		w.markSeen(c, buf.UID)
 		return
 	}
@@ -404,13 +422,14 @@ func (w *IMAPWatcher) processMessage(c *imapclient.Client, buf *imapclient.Fetch
 	// 5. Save task with status RECEIVED.
 	taskUUID := uuid.New().String()
 	task := &database.Task{
-		TaskUUID:  taskUUID,
-		ThreadID:  threadID,
-		MessageID: messageID,
-		Sender:    sender,
-		Subject:   subject,
-		BodyPlain: bodyPlain,
-		Status:    database.StatusReceived,
+		TaskUUID:        taskUUID,
+		ThreadID:        threadID,
+		MessageID:       messageID,
+		Sender:          sender,
+		Subject:         subject,
+		BodyPlain:       bodyPlain,
+		DispatchContext: marshalDispatchContext(ruleResult.Metadata),
+		Status:          database.StatusReceived,
 	}
 
 	taskLog := logging.TaskLogger(taskUUID, threadID, messageID)
@@ -453,19 +472,13 @@ func (w *IMAPWatcher) saveIgnored(messageID, sender, subject, reason string) {
 	}
 }
 
-// isWhitelisted checks if the sender is in the allowed list.
-// Empty whitelist means all senders are allowed.
-func (w *IMAPWatcher) isWhitelisted(sender string) bool {
-	if len(w.cfg.WhitelistEmails) == 0 {
-		return true
+// marshalDispatchContext serializes rule metadata to JSON.
+func marshalDispatchContext(metadata map[string]string) string {
+	if len(metadata) == 0 {
+		return ""
 	}
-	lower := strings.ToLower(sender)
-	for _, email := range w.cfg.WhitelistEmails {
-		if strings.ToLower(email) == lower {
-			return true
-		}
-	}
-	return false
+	data, _ := json.Marshal(metadata)
+	return string(data)
 }
 
 // markSeen flags a message as \Seen in IMAP.
diff --git a/internal/rules/pipeline.go b/internal/rules/pipeline.go
index 63f89bd..d8debb0 100644
--- a/internal/rules/pipeline.go
+++ b/internal/rules/pipeline.go
@@ -27,4 +27,4 @@ func (p *Pipeline) Evaluate(ctx EmailContext) RuleResult {
 		}
 	}
 	return merged
-}
\ No newline at end of file
+}
diff --git a/internal/rules/pipeline_test.go b/internal/rules/pipeline_test.go
index ac37a5f..fe6f951 100644
--- a/internal/rules/pipeline_test.go
+++ b/internal/rules/pipeline_test.go
@@ -95,12 +95,12 @@ type stubRule struct {
 	result RuleResult
 }
 
-func (s *stubRule) Name() string                  { return s.name }
+func (s *stubRule) Name() string                       { return s.name }
 func (s *stubRule) Evaluate(_ EmailContext) RuleResult { return s.result }
 
 type trackingRule struct {
 	called bool
 }
 
-func (t *trackingRule) Name() string                  { return "tracker" }
-func (t *trackingRule) Evaluate(_ EmailContext) RuleResult { t.called = true; return Accept() }
\ No newline at end of file
+func (t *trackingRule) Name() string                       { return "tracker" }
+func (t *trackingRule) Evaluate(_ EmailContext) RuleResult { t.called = true; return Accept() }
diff --git a/internal/rules/types.go b/internal/rules/types.go
index 8c21fe8..3afb3f7 100644
--- a/internal/rules/types.go
+++ b/internal/rules/types.go
@@ -38,4 +38,4 @@ func (r RuleResult) WithMetadata(key, value string) RuleResult {
 type Rule interface {
 	Name() string
 	Evaluate(ctx EmailContext) RuleResult
-}
\ No newline at end of file
+}
diff --git a/internal/rules/types_test.go b/internal/rules/types_test.go
index 2bc2be4..1ac2d9a 100644
--- a/internal/rules/types_test.go
+++ b/internal/rules/types_test.go
@@ -39,4 +39,4 @@ func TestEmailContext_Fields(t *testing.T) {
 	if ctx.Sender != "user@example.com" {
 		t.Fatal("sender mismatch")
 	}
-}
\ No newline at end of file
+}
diff --git a/internal/rules/whitelist.go b/internal/rules/whitelist.go
index 0eaca8a..a3bead9 100644
--- a/internal/rules/whitelist.go
+++ b/internal/rules/whitelist.go
@@ -27,4 +27,4 @@ func (r *WhitelistRule) Evaluate(ctx EmailContext) RuleResult {
 		return Accept()
 	}
 	return Reject("not whitelisted")
-}
\ No newline at end of file
+}