diff --git a/dist/styles/global.css b/dist/styles/global.css
index ffa68be..ff0a129 100644
--- a/dist/styles/global.css
+++ b/dist/styles/global.css
@@ -109,6 +109,10 @@ i.ms-Nav-chevron {
 .ms-ActivityItem-timeStamp {
     color: var(--neutralSecondaryAlt);
 }
+.ms-MessageBar {
+    user-select: none;
+    margin-bottom: 8px;
+}
 
 #root > nav {
     height: var(--navHeight);
diff --git a/src/components/settings/groups.tsx b/src/components/settings/groups.tsx
index 31d2a01..135be72 100644
--- a/src/components/settings/groups.tsx
+++ b/src/components/settings/groups.tsx
@@ -3,12 +3,13 @@ import intl from "react-intl-universal"
 import { SourceGroup } from "../../schema-types"
 import { SourceState, RSSSource } from "../../scripts/models/source"
 import { IColumn, Selection, SelectionMode, DetailsList, Label, Stack,
-     TextField, PrimaryButton, DefaultButton, Dropdown, IDropdownOption, CommandBarButton, MarqueeSelection, IDragDropEvents } from "@fluentui/react"
+     TextField, PrimaryButton, DefaultButton, Dropdown, IDropdownOption, CommandBarButton, MarqueeSelection, IDragDropEvents, MessageBar, MessageBarType } from "@fluentui/react"
 import DangerButton from "../utils/danger-button"
 
 type GroupsTabProps = {
     sources: SourceState,
     groups: SourceGroup[],
+    serviceOn: boolean,
     createGroup: (name: string) => void,
     updateGroup: (group: SourceGroup) => void,
     addToGroup: (groupIndex: number, sid: number) => void,
@@ -263,6 +264,9 @@ class GroupsTab extends React.Component<GroupsTabProps, GroupsTabState> {
 
     render = () => (
         <div className="tab-body">
+            {this.props.serviceOn && (
+                <MessageBar messageBarType={MessageBarType.info}>{intl.get("service.groupsWarning")}</MessageBar>
+            )}
             {this.state.manageGroup && this.state.selectedGroup &&
             <>
                 <Stack horizontal horizontalAlign="space-between" style={{height: 40}}>
diff --git a/src/components/settings/services/fever.tsx b/src/components/settings/services/fever.tsx
index 036802c..cfc0c6f 100644
--- a/src/components/settings/services/fever.tsx
+++ b/src/components/settings/services/fever.tsx
@@ -95,14 +95,12 @@ class FeverConfigsTab extends React.Component<ServiceConfigsTabProps, FeverConfi
 
     render() {
         return <>
-            <Stack tokens={{childrenGap: 8}}>
-                {!this.state.existing && (
-                    <MessageBar messageBarType={MessageBarType.warning}>{intl.get("service.overwriteWarning")}</MessageBar>
-                )}
-                {!this.state.existing && this.state.importGroups && (
-                    <MessageBar messageBarType={MessageBarType.info}>{intl.get("service.groupsWarning")}</MessageBar>
-                )}
-            </Stack>
+            {!this.state.existing && (
+                <MessageBar messageBarType={MessageBarType.warning}>{intl.get("service.overwriteWarning")}</MessageBar>
+            )}
+            {!this.state.existing && this.state.importGroups && (
+                <MessageBar messageBarType={MessageBarType.info}>{intl.get("service.groupsWarning")}</MessageBar>
+            )}
             <Stack horizontalAlign="center" style={{marginTop: 48}}>
                 <Icon iconName="Calories" style={{fontSize: 32, userSelect: "none"}} />
                 <Label style={{margin: "8px 0 36px"}}>Fever API</Label>
diff --git a/src/components/settings/sources.tsx b/src/components/settings/sources.tsx
index 0931785..549b5b9 100644
--- a/src/components/settings/sources.tsx
+++ b/src/components/settings/sources.tsx
@@ -1,13 +1,15 @@
 import * as React from "react"
 import intl from "react-intl-universal"
 import { Label, DefaultButton, TextField, Stack, PrimaryButton, DetailsList, 
-    IColumn, SelectionMode, Selection, IChoiceGroupOption, ChoiceGroup, IDropdownOption, Dropdown } from "@fluentui/react"
+    IColumn, SelectionMode, Selection, IChoiceGroupOption, ChoiceGroup, IDropdownOption, 
+    Dropdown, MessageBar, MessageBarType } from "@fluentui/react"
 import { SourceState, RSSSource, SourceOpenTarget } from "../../scripts/models/source"
 import { urlTest } from "../../scripts/utils"
 import DangerButton from "../utils/danger-button"
 
 type SourcesTabProps = {
     sources: SourceState
+    serviceOn: boolean
     addSource: (url: string) => void
     updateSourceName: (source: RSSSource, name: string) => void
     updateSourceIcon: (source: RSSSource, iconUrl: string) => Promise<void>
@@ -154,6 +156,9 @@ class SourcesTab extends React.Component<SourcesTabProps, SourcesTabState> {
 
     render = () => (
         <div className="tab-body">
+            {this.props.serviceOn && (
+                <MessageBar messageBarType={MessageBarType.info}>{intl.get("sources.serviceWarning")}</MessageBar>
+            )}
             <Label>{intl.get("sources.opmlFile")}</Label>
             <Stack horizontal>
                 <Stack.Item>
@@ -196,6 +201,9 @@ class SourcesTab extends React.Component<SourcesTabProps, SourcesTabState> {
                 selectionMode={SelectionMode.multiple} />
 
             {this.state.selectedSource && <>
+                {this.state.selectedSource.serviceRef && (
+                    <MessageBar messageBarType={MessageBarType.info}>{intl.get("sources.serviceManaged")}</MessageBar>
+                )}
                 <Label>{intl.get("sources.selected")}</Label>
                 <Stack horizontal>
                     <Stack.Item>
@@ -251,34 +259,39 @@ class SourcesTab extends React.Component<SourcesTabProps, SourcesTabState> {
                     </>}
 
                 </Stack>
-                <Label>{intl.get("sources.fetchFrequency")}</Label>
-                <Stack>
-                    <Stack.Item>
-                        <Dropdown
-                            options={this.fetchFrequencyOptions()}
-                            selectedKey={this.state.selectedSource.fetchFrequency ? String(this.state.selectedSource.fetchFrequency) : "0"}
-                            onChange={this.onFetchFrequencyChange}
-                            style={{width: 200}} />
-                    </Stack.Item>
-                </Stack>
+                {!this.state.selectedSource.serviceRef && <>
+                    <Label>{intl.get("sources.fetchFrequency")}</Label>
+                    <Stack>
+                        <Stack.Item>
+                            <Dropdown
+                                options={this.fetchFrequencyOptions()}
+                                selectedKey={this.state.selectedSource.fetchFrequency ? String(this.state.selectedSource.fetchFrequency) : "0"}
+                                onChange={this.onFetchFrequencyChange}
+                                style={{width: 200}} />
+                        </Stack.Item>
+                    </Stack>
+                </>}
                 <ChoiceGroup 
                     label={intl.get("sources.openTarget")} 
                     options={this.sourceOpenTargetChoices()}
                     selectedKey={String(this.state.selectedSource.openTarget)}
                     onChange={this.onOpenTargetChange} />
-                <Stack horizontal>
-                    <Stack.Item>
-                        <DangerButton
-                            onClick={() => this.props.deleteSource(this.state.selectedSource)}
-                            key={this.state.selectedSource.sid}
-                            text={intl.get("sources.delete")} />
-                    </Stack.Item>
-                    <Stack.Item>
-                        <span className="settings-hint">{intl.get("sources.deleteWarning")}</span>
-                    </Stack.Item>
-                </Stack>
+                {!this.state.selectedSource.serviceRef && (
+                    <Stack horizontal>
+                        <Stack.Item>
+                            <DangerButton
+                                onClick={() => this.props.deleteSource(this.state.selectedSource)}
+                                key={this.state.selectedSource.sid}
+                                text={intl.get("sources.delete")} />
+                        </Stack.Item>
+                        <Stack.Item>
+                            <span className="settings-hint">{intl.get("sources.deleteWarning")}</span>
+                        </Stack.Item>
+                    </Stack>
+                )}
             </>}
-            {this.state.selectedSources && <>
+            {this.state.selectedSources && (this.state.selectedSources.filter(s => s.serviceRef).length === 0
+            ? <>
                 <Label>{intl.get("sources.selectedMulti")}</Label>
                 <Stack horizontal>
                     <Stack.Item>
@@ -290,7 +303,10 @@ class SourcesTab extends React.Component<SourcesTabProps, SourcesTabState> {
                         <span className="settings-hint">{intl.get("sources.deleteWarning")}</span>
                     </Stack.Item>
                 </Stack>
-            </>}
+            </>
+            : (
+                <MessageBar messageBarType={MessageBarType.info}>{intl.get("sources.serviceManaged")}</MessageBar>
+            ))}
         </div>
     )
 }
diff --git a/src/containers/settings/groups-container.tsx b/src/containers/settings/groups-container.tsx
index 3cef872..174518e 100644
--- a/src/containers/settings/groups-container.tsx
+++ b/src/containers/settings/groups-container.tsx
@@ -4,16 +4,18 @@ import { RootState } from "../../scripts/reducer"
 import GroupsTab from "../../components/settings/groups"
 import { createSourceGroup, updateSourceGroup, addSourceToGroup,
     deleteSourceGroup, removeSourceFromGroup, reorderSourceGroups } from "../../scripts/models/group"
-import { SourceGroup } from "../../schema-types"
+import { SourceGroup, SyncService } from "../../schema-types"
 
 const getSources = (state: RootState) => state.sources
 const getGroups = (state: RootState) => state.groups
+const getServiceOn = (state: RootState) => state.service.type !== SyncService.None
 
 const mapStateToProps = createSelector(
-    [getSources, getGroups],
-    (sources, groups) => ({
+    [getSources, getGroups, getServiceOn],
+    (sources, groups, serviceOn) => ({
         sources: sources,
         groups: groups.map((g, i) => ({ ...g, index: i })),
+        serviceOn: serviceOn,
         key: groups.length
     })
 )
diff --git a/src/containers/settings/sources-container.tsx b/src/containers/settings/sources-container.tsx
index 72e7b50..b13984b 100644
--- a/src/containers/settings/sources-container.tsx
+++ b/src/containers/settings/sources-container.tsx
@@ -7,13 +7,16 @@ import { addSource, RSSSource, updateSource, deleteSource, SourceOpenTarget, del
 import { importOPML, exportOPML } from "../../scripts/models/group"
 import { AppDispatch, validateFavicon } from "../../scripts/utils"
 import { saveSettings } from "../../scripts/models/app"
+import { SyncService } from "../../schema-types"
 
 const getSources = (state: RootState) => state.sources
+const getServiceOn = (state: RootState) => state.service.type !== SyncService.None
 
 const mapStateToProps = createSelector(
-    [getSources],
-    (sources) => ({
-        sources: sources
+    [getSources, getServiceOn],
+    (sources, serviceOn) => ({
+        sources: sources,
+        serviceOn: serviceOn
     })
 )
 
diff --git a/src/scripts/i18n/en-US.json b/src/scripts/i18n/en-US.json
index cf10048..fa1baec 100644
--- a/src/scripts/i18n/en-US.json
+++ b/src/scripts/i18n/en-US.json
@@ -32,7 +32,8 @@
         "fetchFailure": "Failed to load source \"{name}\".",
         "fetchSuccess": "Successfully fetched {count, plural, =1 {# article} other {# articles}}.",
         "networkError": "A network error has occurred.",
-        "parseError": "An error has occurred when parsing the XML feed."
+        "parseError": "An error has occurred when parsing the XML feed.",
+        "syncFailure": "Failed to sync with service"
     },
     "nav": {
         "menu": "Menu",
@@ -112,6 +113,8 @@
         "feedback": "Feedback"
     },
     "sources": {
+        "serviceWarning": "Sources imported or added here will not be synced with your service.",
+        "serviceManaged": "This source is managed by your service.",
         "untitled": "Source",
         "errorAdd": "An error has occured when adding the source.",
         "errorParse": "An error has occurred when parsing the OPML file.",
diff --git a/src/scripts/i18n/zh-CN.json b/src/scripts/i18n/zh-CN.json
index 263e268..32a49fb 100644
--- a/src/scripts/i18n/zh-CN.json
+++ b/src/scripts/i18n/zh-CN.json
@@ -32,7 +32,8 @@
         "fetchFailure": "无法加载订阅源“{name}”",
         "fetchSuccess": "成功加载 {count} 篇文章",
         "networkError": "连接订阅源时出错",
-        "parseError": "解析XML信息流时出错"
+        "parseError": "解析XML信息流时出错",
+        "syncFailure": "无法与服务同步"
     },
     "nav": {
         "menu": "菜单",
@@ -110,6 +111,8 @@
         "feedback": "反馈"
     },
     "sources": {
+        "serviceWarning": "此处导入或添加的订阅源将不会与服务端同步",
+        "serviceManaged": "该订阅源由服务端管理",
         "untitled": "订阅源",
         "errorAdd": "添加订阅源时出错",
         "errorParse": "解析OPML文件时出错",
@@ -187,7 +190,7 @@
         "fetchLimit": "同步数量",
         "fetchLimitNum": "最近 {count} 篇文章",
         "importGroups": "导入分组",
-        "failure": "无法连接到服务",
+        "failure": "连接到服务时出错",
         "failureHint": "请检查服务配置或网络连接"
     },
     "app": {
diff --git a/src/scripts/models/app.ts b/src/scripts/models/app.ts
index 7932042..21c5eb1 100644
--- a/src/scripts/models/app.ts
+++ b/src/scripts/models/app.ts
@@ -356,6 +356,19 @@ export function appReducer(
                     ...state,
                     syncing: true
                 }
+                case ActionStatus.Failure: return {
+                    ...state,
+                    syncing: false,
+                    logMenu: {
+                        ...state.logMenu,
+                        notify: true,
+                        logs: [...state.logMenu.logs, new AppLog(
+                            AppLogType.Failure,
+                            intl.get("log.syncFailure"),
+                            String(action.err)
+                        )]
+                    }
+                }
                 default: return {
                     ...state,
                     syncing: false
@@ -467,6 +480,7 @@ export function appReducer(
             settings: {
                 ...state.settings,
                 display: true,
+                changed: true,
                 saving: !state.settings.saving
             }
         }