diff --git a/extensions/mattermost/src/channel.ts b/extensions/mattermost/src/channel.ts
index 52f1de4242ca..922063252d2a 100644
--- a/extensions/mattermost/src/channel.ts
+++ b/extensions/mattermost/src/channel.ts
@@ -63,6 +63,7 @@ import { collectRuntimeConfigAssignments, secretTargetRegistryEntries } from "./
 import { resolveMattermostOutboundSessionRoute } from "./session-route.js";
 import { mattermostSetupAdapter } from "./setup-core.js";
 import { mattermostSetupWizard } from "./setup-surface.js";
+import { collectMattermostStatusIssues } from "./status-issues.js";
 import type { MattermostConfig } from "./types.js";
 
 const loadMattermostChannelRuntime = createLazyRuntimeModule(() => import("./channel.runtime.js"));
@@ -834,6 +835,7 @@ export const mattermostPlugin: ChannelPlugin<ResolvedMattermostAccount> = create
         lastConnectedAt: null,
         lastDisconnect: null,
       }),
+      collectStatusIssues: collectMattermostStatusIssues,
       buildChannelSummary: ({ snapshot }) =>
         buildPassiveProbedChannelStatusSummary(snapshot, {
           botTokenSource: snapshot.botTokenSource ?? "none",
@@ -858,6 +860,8 @@ export const mattermostPlugin: ChannelPlugin<ResolvedMattermostAccount> = create
         extra: {
           botTokenSource: account.botTokenSource,
           baseUrl: account.baseUrl,
+          dmPolicy: account.config.dmPolicy ?? "pairing",
+          allowFrom: account.config.allowFrom ?? [],
           connected: runtime?.connected ?? false,
           lastConnectedAt: runtime?.lastConnectedAt ?? null,
           lastDisconnect: runtime?.lastDisconnect ?? null,
diff --git a/extensions/mattermost/src/config-schema.test.ts b/extensions/mattermost/src/config-schema.test.ts
index fc4f4a648c36..30512cf9ef19 100644
--- a/extensions/mattermost/src/config-schema.test.ts
+++ b/extensions/mattermost/src/config-schema.test.ts
@@ -30,6 +30,21 @@ describe("MattermostConfigSchema", () => {
     expect(result.success).toBe(true);
   });
 
+  it('rejects dmPolicy="open" without wildcard allowFrom', () => {
+    const result = MattermostConfigSchema.safeParse({
+      dmPolicy: "open",
+    });
+    expect(result.success).toBe(false);
+  });
+
+  it('accepts dmPolicy="open" with wildcard allowFrom', () => {
+    const result = MattermostConfigSchema.safeParse({
+      dmPolicy: "open",
+      allowFrom: ["*"],
+    });
+    expect(result.success).toBe(true);
+  });
+
   it("accepts documented streaming modes and progress config", () => {
     const result = MattermostConfigSchema.safeParse({
       streaming: {
diff --git a/extensions/mattermost/src/mattermost/monitor-auth.test.ts b/extensions/mattermost/src/mattermost/monitor-auth.test.ts
index 3f685ffc936a..4cce0e3de643 100644
--- a/extensions/mattermost/src/mattermost/monitor-auth.test.ts
+++ b/extensions/mattermost/src/mattermost/monitor-auth.test.ts
@@ -11,6 +11,7 @@ vi.mock("./runtime-api.js", () => ({
 
 describe("mattermost monitor auth", () => {
   let authorizeMattermostCommandInvocation: typeof import("./monitor-auth.js").authorizeMattermostCommandInvocation;
+  let formatMattermostDirectMessageDropLog: typeof import("./monitor-auth.js").formatMattermostDirectMessageDropLog;
   let isMattermostSenderAllowed: typeof import("./monitor-auth.js").isMattermostSenderAllowed;
   let normalizeMattermostAllowEntry: typeof import("./monitor-auth.js").normalizeMattermostAllowEntry;
   let normalizeMattermostAllowList: typeof import("./monitor-auth.js").normalizeMattermostAllowList;
@@ -18,6 +19,7 @@ describe("mattermost monitor auth", () => {
   beforeAll(async () => {
     ({
       authorizeMattermostCommandInvocation,
+      formatMattermostDirectMessageDropLog,
       isMattermostSenderAllowed,
       normalizeMattermostAllowEntry,
       normalizeMattermostAllowList,
@@ -58,6 +60,18 @@ describe("mattermost monitor auth", () => {
     });
   });
 
+  it("formats direct-message drops with the ingress reason and open-policy hint", () => {
+    expect(
+      formatMattermostDirectMessageDropLog({
+        senderId: "alice-id",
+        dmPolicy: "open",
+        reasonCode: "dm_policy_not_allowlisted",
+      }),
+    ).toBe(
+      "mattermost: drop dm sender=alice-id (dmPolicy=open reason=dm_policy_not_allowlisted hint=add-allowFrom-wildcard)",
+    );
+  });
+
   it("resolves direct command authorization from shared ingress", async () => {
     isDangerousNameMatchingEnabled.mockReturnValue(false);
     resolveAllowlistMatchSimple.mockReturnValue({ allowed: false });
diff --git a/extensions/mattermost/src/mattermost/monitor-auth.ts b/extensions/mattermost/src/mattermost/monitor-auth.ts
index f642b91190ce..35af70771c51 100644
--- a/extensions/mattermost/src/mattermost/monitor-auth.ts
+++ b/extensions/mattermost/src/mattermost/monitor-auth.ts
@@ -61,6 +61,19 @@ export function normalizeMattermostAllowList(entries: Array<string | number>): s
   return uniqueStrings(normalized);
 }
 
+export function formatMattermostDirectMessageDropLog(params: {
+  senderId: string;
+  dmPolicy: string;
+  reasonCode?: string;
+}): string {
+  const reason = params.reasonCode ? ` reason=${params.reasonCode}` : "";
+  const hint =
+    params.dmPolicy === "open" && params.reasonCode === "dm_policy_not_allowlisted"
+      ? " hint=add-allowFrom-wildcard"
+      : "";
+  return `mattermost: drop dm sender=${params.senderId} (dmPolicy=${params.dmPolicy}${reason}${hint})`;
+}
+
 export function isMattermostSenderAllowed(params: {
   senderId: string;
   senderName?: string;
diff --git a/extensions/mattermost/src/mattermost/monitor.ts b/extensions/mattermost/src/mattermost/monitor.ts
index 28f25852449b..7fe93a4264a9 100644
--- a/extensions/mattermost/src/mattermost/monitor.ts
+++ b/extensions/mattermost/src/mattermost/monitor.ts
@@ -57,6 +57,7 @@ import {
 } from "./model-picker.js";
 import {
   authorizeMattermostCommandInvocation,
+  formatMattermostDirectMessageDropLog,
   normalizeMattermostAllowEntry,
   resolveMattermostMonitorInboundAccess,
 } from "./monitor-auth.js";
@@ -1391,7 +1392,13 @@ export async function monitorMattermostProvider(opts: MonitorMattermostOpts = {}
               }
               return;
             }
-            logVerboseMessage(`mattermost: drop dm sender=${senderId} (dmPolicy=${dmPolicy})`);
+            logVerboseMessage(
+              formatMattermostDirectMessageDropLog({
+                senderId,
+                dmPolicy,
+                reasonCode: accessDecision.senderAccess.reasonCode,
+              }),
+            );
             return;
           }
           if (accessDecision.ingress.reasonCode === "group_policy_disabled") {
diff --git a/extensions/mattermost/src/status-issues.test.ts b/extensions/mattermost/src/status-issues.test.ts
new file mode 100644
index 000000000000..b2d915a7e38b
--- /dev/null
+++ b/extensions/mattermost/src/status-issues.test.ts
@@ -0,0 +1,32 @@
+// Mattermost tests cover status issues plugin behavior.
+import { expectOpenDmPolicyConfigIssue } from "openclaw/plugin-sdk/channel-test-helpers";
+import { describe, expect, it } from "vitest";
+import { collectMattermostStatusIssues } from "./status-issues.js";
+
+describe("collectMattermostStatusIssues", () => {
+  it("warns when dmPolicy is open without a wildcard allowlist", () => {
+    expectOpenDmPolicyConfigIssue({
+      collectIssues: collectMattermostStatusIssues,
+      account: {
+        accountId: "default",
+        enabled: true,
+        configured: true,
+        dmPolicy: "open",
+      },
+    });
+  });
+
+  it("allows open dmPolicy when allowFrom includes the wildcard", () => {
+    expect(
+      collectMattermostStatusIssues([
+        {
+          accountId: "default",
+          enabled: true,
+          configured: true,
+          dmPolicy: "open",
+          allowFrom: ["*"],
+        },
+      ]),
+    ).toEqual([]);
+  });
+});
diff --git a/extensions/mattermost/src/status-issues.ts b/extensions/mattermost/src/status-issues.ts
new file mode 100644
index 000000000000..4a219765770a
--- /dev/null
+++ b/extensions/mattermost/src/status-issues.ts
@@ -0,0 +1,51 @@
+// Mattermost plugin module implements status issue collection.
+import type {
+  ChannelAccountSnapshot,
+  ChannelStatusIssue,
+} from "openclaw/plugin-sdk/channel-contract";
+import {
+  coerceStatusIssueAccountId,
+  readStatusIssueFields,
+} from "openclaw/plugin-sdk/extension-shared";
+
+const MATTERMOST_STATUS_FIELDS = [
+  "accountId",
+  "enabled",
+  "configured",
+  "dmPolicy",
+  "allowFrom",
+] as const;
+
+function hasWildcardAllowFrom(value: unknown): boolean {
+  return Array.isArray(value) && value.some((entry) => String(entry).trim() === "*");
+}
+
+export function collectMattermostStatusIssues(
+  accounts: ChannelAccountSnapshot[],
+): ChannelStatusIssue[] {
+  const issues: ChannelStatusIssue[] = [];
+  for (const entry of accounts) {
+    const account = readStatusIssueFields(entry, MATTERMOST_STATUS_FIELDS);
+    if (!account) {
+      continue;
+    }
+    const accountId = coerceStatusIssueAccountId(account.accountId) ?? "default";
+    const enabled = account.enabled !== false;
+    const configured = account.configured === true;
+    if (!enabled || !configured) {
+      continue;
+    }
+
+    if (account.dmPolicy === "open" && !hasWildcardAllowFrom(account.allowFrom)) {
+      issues.push({
+        channel: "mattermost",
+        accountId,
+        kind: "config",
+        message:
+          'Mattermost dmPolicy is "open" but allowFrom does not include "*"; public DMs will be dropped.',
+        fix: 'Add "*" to channels.mattermost.allowFrom (or the account-specific allowFrom) or set dmPolicy to "pairing"/"allowlist".',
+      });
+    }
+  }
+  return issues;
+}
diff --git a/src/config/validation.channel-metadata.test.ts b/src/config/validation.channel-metadata.test.ts
index 9b87b78026d5..58b201d23ee5 100644
--- a/src/config/validation.channel-metadata.test.ts
+++ b/src/config/validation.channel-metadata.test.ts
@@ -284,6 +284,60 @@ describe("validateConfigObjectWithPlugins channel metadata (applyDefaults: true)
       expect(result.config.channels?.discord?.accounts?.work?.agentComponents?.ttlMs).toBe(60_000);
     }
   });
+
+  it('rejects Mattermost dmPolicy="open" without wildcard allowFrom', () => {
+    const result = validateConfigObjectWithPlugins({
+      channels: {
+        mattermost: {
+          enabled: true,
+          baseUrl: "https://chat.example.com",
+          botToken: "test-token",
+          dmPolicy: "open",
+        },
+      },
+    });
+
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.issues).toContainEqual(
+        expect.objectContaining({
+          path: "channels.mattermost.allowFrom",
+          message: expect.stringContaining(
+            'channels.mattermost.dmPolicy="open" requires channels.mattermost.allowFrom to include "*"',
+          ),
+        }),
+      );
+    }
+  });
+
+  it('rejects account-scoped Mattermost dmPolicy="open" without wildcard allowFrom', () => {
+    const result = validateConfigObjectWithPlugins({
+      channels: {
+        mattermost: {
+          accounts: {
+            work: {
+              enabled: true,
+              baseUrl: "https://chat.example.com",
+              botToken: "test-token",
+              dmPolicy: "open",
+            },
+          },
+        },
+      },
+    });
+
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.issues).toContainEqual(
+        expect.objectContaining({
+          path: "channels.mattermost.accounts.work.allowFrom",
+          message: expect.stringContaining(
+            'channels.mattermost.accounts.work.dmPolicy="open" requires channels.mattermost.accounts.work.allowFrom to include "*"',
+          ),
+        }),
+      );
+    }
+  });
 });
 
 describe("validateConfigObjectRawWithPlugins channel metadata", () => {
diff --git a/src/config/validation.ts b/src/config/validation.ts
index 2fdcc6f7df39..b27b2179a8f0 100644
--- a/src/config/validation.ts
+++ b/src/config/validation.ts
@@ -311,6 +311,56 @@ function collectAllowedValuesFromBundledChannelSchemaPath(
 function formatRawChannelConfigIssueMessage(message: string): string {
   return `invalid config: ${message}`;
 }
+
+function hasWildcardAllowFrom(value: unknown): boolean {
+  return Array.isArray(value) && value.some((entry) => String(entry).trim() === "*");
+}
+
+function collectMattermostOpenDmAllowFromIssues(
+  value: unknown,
+  pathPrefix: string,
+): ConfigValidationIssue[] {
+  if (!isRecord(value)) {
+    return [];
+  }
+  const issues: ConfigValidationIssue[] = [];
+  if (value.dmPolicy === "open" && !hasWildcardAllowFrom(value.allowFrom)) {
+    issues.push({
+      path: `${pathPrefix}.allowFrom`,
+      message: formatRawChannelConfigIssueMessage(
+        `${pathPrefix}.dmPolicy="open" requires ${pathPrefix}.allowFrom to include "*"`,
+      ),
+    });
+  }
+  if (isRecord(value.accounts)) {
+    for (const [accountId, accountConfig] of Object.entries(value.accounts)) {
+      if (!isRecord(accountConfig)) {
+        continue;
+      }
+      const accountPath = `${pathPrefix}.accounts.${accountId}`;
+      if (accountConfig.dmPolicy === "open" && !hasWildcardAllowFrom(accountConfig.allowFrom)) {
+        issues.push({
+          path: `${accountPath}.allowFrom`,
+          message: formatRawChannelConfigIssueMessage(
+            `${accountPath}.dmPolicy="open" requires ${accountPath}.allowFrom to include "*"`,
+          ),
+        });
+      }
+    }
+  }
+  return issues;
+}
+
+function collectBundledChannelConfigDependencyIssues(
+  channelId: string,
+  value: unknown,
+): ConfigValidationIssue[] {
+  if (channelId === "mattermost") {
+    return collectMattermostOpenDmAllowFromIssues(value, "channels.mattermost");
+  }
+  return [];
+}
+
 function collectRawBundledChannelConfigIssues(config: OpenClawConfig): ConfigValidationIssue[] {
   if (!config.channels || !isRecord(config.channels)) {
     return [];
@@ -320,6 +370,9 @@ function collectRawBundledChannelConfigIssues(config: OpenClawConfig): ConfigVal
     if (!Object.hasOwn(config.channels, channelId)) {
       continue;
     }
+    issues.push(
+      ...collectBundledChannelConfigDependencyIssues(channelId, config.channels[channelId]),
+    );
     const result = validateJsonSchemaValue({
       schema: schema as Record<string, unknown>,
       cacheKey: `raw-channel:${channelId}`,
@@ -1569,6 +1622,7 @@ function validateConfigObjectWithPluginsBase(
         }
         continue;
       }
+      issues.push(...collectBundledChannelConfigDependencyIssues(trimmed, result.value));
       replaceChannelConfig(trimmed, result.value);
     }
   }