diff --git a/src/infra/outbound/channel-selection.test.ts b/src/infra/outbound/channel-selection.test.ts
index da605dcdb63..9448b919312 100644
--- a/src/infra/outbound/channel-selection.test.ts
+++ b/src/infra/outbound/channel-selection.test.ts
@@ -2,12 +2,17 @@ import { beforeEach, describe, expect, it, vi } from "vitest";
 
 const mocks = vi.hoisted(() => ({
   listChannelPlugins: vi.fn(),
+  resolveOutboundChannelPlugin: vi.fn(),
 }));
 
 vi.mock("../../channels/plugins/index.js", () => ({
   listChannelPlugins: mocks.listChannelPlugins,
 }));
 
+vi.mock("./channel-resolution.js", () => ({
+  resolveOutboundChannelPlugin: mocks.resolveOutboundChannelPlugin,
+}));
+
 import {
   listConfiguredMessageChannels,
   resolveMessageChannelSelection,
@@ -36,6 +41,10 @@ describe("listConfiguredMessageChannels", () => {
   beforeEach(() => {
     mocks.listChannelPlugins.mockReset();
     mocks.listChannelPlugins.mockReturnValue([]);
+    mocks.resolveOutboundChannelPlugin.mockReset();
+    mocks.resolveOutboundChannelPlugin.mockImplementation(({ channel }: { channel: string }) => ({
+      id: channel,
+    }));
   });
 
   it("skips unknown plugin ids and plugins without accounts", async () => {
@@ -158,6 +167,35 @@ describe("resolveMessageChannelSelection", () => {
     ).rejects.toThrow("Unknown channel: channel:c123");
   });
 
+  it("falls back when the explicit known channel is unavailable in the active plugin registry", async () => {
+    mocks.resolveOutboundChannelPlugin.mockImplementation(({ channel }: { channel: string }) =>
+      channel === "slack" ? { id: "slack" } : undefined,
+    );
+
+    const selection = await resolveMessageChannelSelection({
+      cfg: {} as never,
+      channel: "discord",
+      fallbackChannel: "slack",
+    });
+
+    expect(selection).toEqual({
+      channel: "slack",
+      configured: [],
+      source: "tool-context-fallback",
+    });
+  });
+
+  it("throws unavailable when a known channel has no active plugin", async () => {
+    mocks.resolveOutboundChannelPlugin.mockReturnValue(undefined);
+
+    await expect(
+      resolveMessageChannelSelection({
+        cfg: {} as never,
+        channel: "discord",
+      }),
+    ).rejects.toThrow("Channel is unavailable: discord");
+  });
+
   it("throws when no channel is provided and nothing is configured", async () => {
     await expect(
       resolveMessageChannelSelection({
diff --git a/src/infra/outbound/channel-selection.ts b/src/infra/outbound/channel-selection.ts
index 9fbd592a589..024fc2273f6 100644
--- a/src/infra/outbound/channel-selection.ts
+++ b/src/infra/outbound/channel-selection.ts
@@ -7,6 +7,7 @@ import {
   isDeliverableMessageChannel,
   normalizeMessageChannel,
 } from "../../utils/message-channel.js";
+import { resolveOutboundChannelPlugin } from "./channel-resolution.js";
 
 export type MessageChannelId = DeliverableMessageChannel;
 export type MessageChannelSelectionSource =
@@ -34,6 +35,22 @@ function resolveKnownChannel(value?: string | null): MessageChannelId | undefine
   return normalized as MessageChannelId;
 }
 
+function resolveAvailableKnownChannel(params: {
+  cfg: OpenClawConfig;
+  value?: string | null;
+}): MessageChannelId | undefined {
+  const normalized = resolveKnownChannel(params.value);
+  if (!normalized) {
+    return undefined;
+  }
+  return resolveOutboundChannelPlugin({
+    channel: normalized,
+    cfg: params.cfg,
+  })
+    ? normalized
+    : undefined;
+}
+
 function isAccountEnabled(account: unknown): boolean {
   if (!account || typeof account !== "object") {
     return true;
@@ -94,8 +111,15 @@ export async function resolveMessageChannelSelection(params: {
 }> {
   const normalized = normalizeMessageChannel(params.channel);
   if (normalized) {
-    if (!isKnownChannel(normalized)) {
-      const fallback = resolveKnownChannel(params.fallbackChannel);
+    const availableExplicit = resolveAvailableKnownChannel({
+      cfg: params.cfg,
+      value: normalized,
+    });
+    if (!availableExplicit) {
+      const fallback = resolveAvailableKnownChannel({
+        cfg: params.cfg,
+        value: params.fallbackChannel,
+      });
       if (fallback) {
         return {
           channel: fallback,
@@ -103,16 +127,22 @@ export async function resolveMessageChannelSelection(params: {
           source: "tool-context-fallback",
         };
       }
-      throw new Error(`Unknown channel: ${String(normalized)}`);
+      if (!isKnownChannel(normalized)) {
+        throw new Error(`Unknown channel: ${String(normalized)}`);
+      }
+      throw new Error(`Channel is unavailable: ${String(normalized)}`);
     }
     return {
-      channel: normalized as MessageChannelId,
+      channel: availableExplicit,
       configured: await listConfiguredMessageChannels(params.cfg),
       source: "explicit",
     };
   }
 
-  const fallback = resolveKnownChannel(params.fallbackChannel);
+  const fallback = resolveAvailableKnownChannel({
+    cfg: params.cfg,
+    value: params.fallbackChannel,
+  });
   if (fallback) {
     return {
       channel: fallback,
diff --git a/src/infra/outbound/message-action-runner.ts b/src/infra/outbound/message-action-runner.ts
index 0b6ad1ba16e..088baf75c22 100644
--- a/src/infra/outbound/message-action-runner.ts
+++ b/src/infra/outbound/message-action-runner.ts
@@ -20,6 +20,7 @@ import { buildChannelAccountBindings } from "../../routing/bindings.js";
 import { normalizeAgentId } from "../../routing/session-key.js";
 import { type GatewayClientMode, type GatewayClientName } from "../../utils/message-channel.js";
 import { throwIfAborted } from "./abort.js";
+import { resolveOutboundChannelPlugin } from "./channel-resolution.js";
 import {
   listConfiguredMessageChannels,
   resolveMessageChannelSelection,
@@ -670,6 +671,11 @@ async function handlePluginAction(ctx: ResolvedActionContext): Promise<MessageAc
     };
   }
 
+  const plugin = resolveOutboundChannelPlugin({ channel, cfg });
+  if (!plugin?.actions?.handleAction) {
+    throw new Error(`Channel ${channel} is unavailable for message actions (plugin not loaded).`);
+  }
+
   const handled = await dispatchChannelMessageAction({
     channel,
     action,