diff --git a/lib/keyserver-conn/keyserver-call-utils.js b/lib/keyserver-conn/keyserver-call-utils.js
--- a/lib/keyserver-conn/keyserver-call-utils.js
+++ b/lib/keyserver-conn/keyserver-call-utils.js
@@ -86,8 +86,22 @@
   return results;
 }
 
+function getThreadIDsForKeyservers(
+  threadIDs: $ReadOnlyArray<string>,
+  keyserverIDs: $ReadOnlyArray<string>,
+): $ReadOnlyArray<string> {
+  if (keyserverIDs.length === 0) {
+    return [];
+  }
+  const keyserverIDsSet = new Set<string>(keyserverIDs);
+  return threadIDs.filter(threadID =>
+    keyserverIDsSet.has(extractKeyserverIDFromID(threadID)),
+  );
+}
+
 export {
   extractKeyserverIDFromID,
   sortThreadIDsPerKeyserver,
   sortCalendarQueryPerKeyserver,
+  getThreadIDsForKeyservers,
 };
diff --git a/lib/keyserver-conn/keyserver-call-utils.test.js b/lib/keyserver-conn/keyserver-call-utils.test.js
--- a/lib/keyserver-conn/keyserver-call-utils.test.js
+++ b/lib/keyserver-conn/keyserver-call-utils.test.js
@@ -3,6 +3,7 @@
 import {
   extractKeyserverIDFromID,
   sortCalendarQueryPerKeyserver,
+  getThreadIDsForKeyservers,
 } from './keyserver-call-utils.js';
 import type { CalendarQuery } from '../types/entry-types';
 
@@ -86,3 +87,37 @@
     );
   });
 });
+
+const keyserver1 = '256';
+const keyserver2 = '100';
+const keyserver3 = '200';
+const keyserver1ThreadIDs = [
+  keyserver1 + '|1',
+  keyserver1 + '|2',
+  keyserver1 + '|3',
+];
+const keyserver2ThreadIDs = [
+  keyserver2 + '|1',
+  keyserver2 + '|2',
+  keyserver2 + '|3',
+];
+const keyserver3ThreadIDs = [
+  keyserver3 + '|1',
+  keyserver3 + '|2',
+  keyserver3 + '|3',
+];
+
+describe('getThreadIDsForKeyservers', () => {
+  it('should return thread belonging to specified keyservers', () => {
+    expect(
+      getThreadIDsForKeyservers(
+        [
+          ...keyserver1ThreadIDs,
+          ...keyserver2ThreadIDs,
+          ...keyserver3ThreadIDs,
+        ],
+        [keyserver1, keyserver2],
+      ),
+    ).toEqual([...keyserver1ThreadIDs, ...keyserver2ThreadIDs]);
+  });
+});
diff --git a/lib/reducers/thread-reducer.js b/lib/reducers/thread-reducer.js
--- a/lib/reducers/thread-reducer.js
+++ b/lib/reducers/thread-reducer.js
@@ -19,12 +19,14 @@
   deleteCommunityRoleActionTypes,
 } from '../actions/thread-actions.js';
 import {
+  keyserverAuthActionTypes,
   logOutActionTypes,
   deleteKeyserverAccountActionTypes,
   logInActionTypes,
   keyserverRegisterActionTypes,
   updateSubscriptionActionTypes,
 } from '../actions/user-actions.js';
+import { getThreadIDsForKeyservers } from '../keyserver-conn/keyserver-call-utils.js';
 import { setNewSessionActionType } from '../keyserver-conn/keyserver-conn-types.js';
 import {
   type ThreadStoreOperation,
@@ -106,12 +108,34 @@
       newThreadInconsistencies: [],
       threadStoreOperations,
     };
-  } else if (
-    action.type === logOutActionTypes.success ||
-    action.type === deleteKeyserverAccountActionTypes.success ||
-    (action.type === setNewSessionActionType &&
-      action.payload.sessionChange.cookieInvalidated)
-  ) {
+  } else if (action.type === keyserverAuthActionTypes.success) {
+    const keyserverIDs = Object.keys(action.payload.updatesCurrentAsOf);
+    const threadIDsToRemove = getThreadIDsForKeyservers(
+      Object.keys(state.threadInfos),
+      keyserverIDs,
+    );
+    const newThreadInfos = action.payload.threadInfos;
+
+    const threadStoreOperations = [
+      {
+        type: 'remove',
+        payload: { ids: threadIDsToRemove },
+      },
+      ...Object.keys(newThreadInfos).map((id: string) => ({
+        type: 'replace',
+        payload: { id, threadInfo: newThreadInfos[id] },
+      })),
+    ];
+    const updatedThreadStore = processThreadStoreOperations(
+      state,
+      threadStoreOperations,
+    );
+    return {
+      threadStore: updatedThreadStore,
+      newThreadInconsistencies: [],
+      threadStoreOperations,
+    };
+  } else if (action.type === logOutActionTypes.success) {
     if (Object.keys(state.threadInfos).length === 0) {
       return {
         threadStore: state,
@@ -133,6 +157,67 @@
       newThreadInconsistencies: [],
       threadStoreOperations,
     };
+  } else if (action.type === deleteKeyserverAccountActionTypes.success) {
+    const threadIDsToRemove = getThreadIDsForKeyservers(
+      Object.keys(state.threadInfos),
+      action.payload.keyserverIDs,
+    );
+
+    if (threadIDsToRemove.length === 0) {
+      return {
+        threadStore: state,
+        newThreadInconsistencies: [],
+        threadStoreOperations: [],
+      };
+    }
+
+    const threadStoreOperations = [
+      {
+        type: 'remove',
+        payload: { ids: threadIDsToRemove },
+      },
+    ];
+    const updatedThreadStore = processThreadStoreOperations(
+      state,
+      threadStoreOperations,
+    );
+    return {
+      threadStore: updatedThreadStore,
+      newThreadInconsistencies: [],
+      threadStoreOperations,
+    };
+  } else if (
+    action.type === setNewSessionActionType &&
+    action.payload.sessionChange.cookieInvalidated
+  ) {
+    const threadIDsToRemove = getThreadIDsForKeyservers(
+      Object.keys(state.threadInfos),
+      [action.payload.keyserverID],
+    );
+
+    if (threadIDsToRemove.length === 0) {
+      return {
+        threadStore: state,
+        newThreadInconsistencies: [],
+        threadStoreOperations: [],
+      };
+    }
+
+    const threadStoreOperations = [
+      {
+        type: 'remove',
+        payload: { ids: threadIDsToRemove },
+      },
+    ];
+    const updatedThreadStore = processThreadStoreOperations(
+      state,
+      threadStoreOperations,
+    );
+    return {
+      threadStore: updatedThreadStore,
+      newThreadInconsistencies: [],
+      threadStoreOperations,
+    };
   } else if (
     action.type === joinThreadActionTypes.success ||
     action.type === leaveThreadActionTypes.success ||