diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f0fd24c4..72c3b22d6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,7 @@
 - Enhance: フォロワーへのメッセージ欄のデザイン改良
 
 ### Server
--
+- Enhance: セキュリティ向上のため、ログイン時にメール通知を行うように
 
 
 ## 2024.9.0
diff --git a/locales/index.d.ts b/locales/index.d.ts
index 29c93453f..0a9123f03 100644
--- a/locales/index.d.ts
+++ b/locales/index.d.ts
@@ -9285,6 +9285,10 @@ export interface Locale extends ILocale {
          * {x}のエクスポートが完了しました
          */
         "exportOfXCompleted": ParameterizedString<"x">;
+        /**
+         * ログインがありました
+         */
+        "login": string;
         "_types": {
             /**
              * すべて
@@ -9342,6 +9346,10 @@ export interface Locale extends ILocale {
              * エクスポートが完了した
              */
             "exportCompleted": string;
+            /**
+             * ログイン
+             */
+            "login": string;
             /**
              * 通知のテスト
              */
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index 678af6987..cfbe0dcc7 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -2451,6 +2451,7 @@ _notification:
   followedBySomeUsers: "{n}人にフォローされました"
   flushNotification: "通知の履歴をリセットする"
   exportOfXCompleted: "{x}のエクスポートが完了しました"
+  login: "ログインがありました"
 
   _types:
     all: "すべて"
@@ -2467,6 +2468,7 @@ _notification:
     roleAssigned: "ロールが付与された"
     achievementEarned: "実績の獲得"
     exportCompleted: "エクスポートが完了した"
+    login: "ログイン"
     test: "通知のテスト"
     app: "連携アプリからの通知"
 
diff --git a/packages/backend/assets/tabler-badges/login-2.png b/packages/backend/assets/tabler-badges/login-2.png
new file mode 100644
index 000000000..f3ca8de3d
Binary files /dev/null and b/packages/backend/assets/tabler-badges/login-2.png differ
diff --git a/packages/backend/src/models/Notification.ts b/packages/backend/src/models/Notification.ts
index c1d3d4213..b7f8e94d6 100644
--- a/packages/backend/src/models/Notification.ts
+++ b/packages/backend/src/models/Notification.ts
@@ -3,12 +3,12 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
+import { userExportableEntities } from '@/types.js';
 import { MiUser } from './User.js';
 import { MiNote } from './Note.js';
 import { MiAccessToken } from './AccessToken.js';
 import { MiRole } from './Role.js';
 import { MiDriveFile } from './DriveFile.js';
-import { userExportableEntities } from '@/types.js';
 
 export type MiNotification = {
 	type: 'note';
@@ -86,6 +86,10 @@ export type MiNotification = {
 	createdAt: string;
 	exportedEntity: typeof userExportableEntities[number];
 	fileId: MiDriveFile['id'];
+} | {
+	type: 'login';
+	id: string;
+	createdAt: string;
 } | {
 	type: 'app';
 	id: string;
diff --git a/packages/backend/src/models/json-schema/notification.ts b/packages/backend/src/models/json-schema/notification.ts
index 264501049..cddaf4bc8 100644
--- a/packages/backend/src/models/json-schema/notification.ts
+++ b/packages/backend/src/models/json-schema/notification.ts
@@ -322,6 +322,16 @@ export const packedNotificationSchema = {
 				format: 'id',
 			},
 		},
+	}, {
+		type: 'object',
+		properties: {
+			...baseSchema.properties,
+			type: {
+				type: 'string',
+				optional: false, nullable: false,
+				enum: ['login'],
+			},
+		},
 	}, {
 		type: 'object',
 		properties: {
diff --git a/packages/backend/src/server/api/SigninService.ts b/packages/backend/src/server/api/SigninService.ts
index 70306c311..4b041f373 100644
--- a/packages/backend/src/server/api/SigninService.ts
+++ b/packages/backend/src/server/api/SigninService.ts
@@ -5,12 +5,14 @@
 
 import { Inject, Injectable } from '@nestjs/common';
 import { DI } from '@/di-symbols.js';
-import type { SigninsRepository } from '@/models/_.js';
+import type { SigninsRepository, UserProfilesRepository } from '@/models/_.js';
 import { IdService } from '@/core/IdService.js';
 import type { MiLocalUser } from '@/models/User.js';
 import { GlobalEventService } from '@/core/GlobalEventService.js';
 import { SigninEntityService } from '@/core/entities/SigninEntityService.js';
 import { bindThis } from '@/decorators.js';
+import { EmailService } from '@/core/EmailService.js';
+import { NotificationService } from '@/core/NotificationService.js';
 import type { FastifyRequest, FastifyReply } from 'fastify';
 
 @Injectable()
@@ -19,7 +21,12 @@ export class SigninService {
 		@Inject(DI.signinsRepository)
 		private signinsRepository: SigninsRepository,
 
+		@Inject(DI.userProfilesRepository)
+		private userProfilesRepository: UserProfilesRepository,
+
 		private signinEntityService: SigninEntityService,
+		private emailService: EmailService,
+		private notificationService: NotificationService,
 		private idService: IdService,
 		private globalEventService: GlobalEventService,
 	) {
@@ -28,7 +35,8 @@ export class SigninService {
 	@bindThis
 	public signin(request: FastifyRequest, reply: FastifyReply, user: MiLocalUser) {
 		setImmediate(async () => {
-			// Append signin history
+			this.notificationService.createNotification(user.id, 'login', {});
+
 			const record = await this.signinsRepository.insertOne({
 				id: this.idService.gen(),
 				userId: user.id,
@@ -37,8 +45,14 @@ export class SigninService {
 				success: true,
 			});
 
-			// Publish signin event
 			this.globalEventService.publishMainStream(user.id, 'signin', await this.signinEntityService.pack(record));
+
+			const profile = await this.userProfilesRepository.findOneByOrFail({ userId: user.id });
+			if (profile.email && profile.emailVerified) {
+				this.emailService.sendEmail(profile.email, 'New login / ログインがありました',
+					'There is a new login. If you do not recognize this login, update the security status of your account, including changing your password. / 新しいログインがありました。このログインに心当たりがない場合は、パスワードを変更するなど、アカウントのセキュリティ状態を更新してください。',
+					'There is a new login. If you do not recognize this login, update the security status of your account, including changing your password. / 新しいログインがありました。このログインに心当たりがない場合は、パスワードを変更するなど、アカウントのセキュリティ状態を更新してください。');
+			}
 		});
 
 		reply.code(200);
diff --git a/packages/backend/src/types.ts b/packages/backend/src/types.ts
index 5854c6b39..0389143da 100644
--- a/packages/backend/src/types.ts
+++ b/packages/backend/src/types.ts
@@ -17,6 +17,7 @@
  * roleAssigned - ロールが付与された
  * achievementEarned - 実績を獲得
  * exportCompleted - エクスポートが完了
+ * login - ログイン
  * app - アプリ通知
  * test - テスト通知(サーバー側)
  */
@@ -34,6 +35,7 @@ export const notificationTypes = [
 	'roleAssigned',
 	'achievementEarned',
 	'exportCompleted',
+	'login',
 	'app',
 	'test',
 ] as const;
diff --git a/packages/frontend-shared/js/const.ts b/packages/frontend-shared/js/const.ts
index aec4a4a58..4fe5cbb20 100644
--- a/packages/frontend-shared/js/const.ts
+++ b/packages/frontend-shared/js/const.ts
@@ -68,6 +68,7 @@ export const notificationTypes = [
 	'roleAssigned',
 	'achievementEarned',
 	'exportCompleted',
+	'login',
 	'test',
 	'app',
 ] as const;
diff --git a/packages/frontend/src/components/MkNotification.vue b/packages/frontend/src/components/MkNotification.vue
index 12c2974de..b27d883b8 100644
--- a/packages/frontend/src/components/MkNotification.vue
+++ b/packages/frontend/src/components/MkNotification.vue
@@ -7,13 +7,12 @@ SPDX-License-Identifier: AGPL-3.0-only
 <div :class="$style.root">
 	<div :class="$style.head">
 		<MkAvatar v-if="['pollEnded', 'note'].includes(notification.type) && 'note' in notification" :class="$style.icon" :user="notification.note.user" link preview/>
-		<MkAvatar v-else-if="['roleAssigned', 'achievementEarned'].includes(notification.type)" :class="$style.icon" :user="$i" link preview/>
+		<MkAvatar v-else-if="['roleAssigned', 'achievementEarned', 'exportCompleted', 'login'].includes(notification.type)" :class="$style.icon" :user="$i" link preview/>
 		<div v-else-if="notification.type === 'reaction:grouped' && notification.note.reactionAcceptance === 'likeOnly'" :class="[$style.icon, $style.icon_reactionGroupHeart]"><i class="ti ti-heart" style="line-height: 1;"></i></div>
 		<div v-else-if="notification.type === 'reaction:grouped'" :class="[$style.icon, $style.icon_reactionGroup]"><i class="ti ti-plus" style="line-height: 1;"></i></div>
 		<div v-else-if="notification.type === 'renote:grouped'" :class="[$style.icon, $style.icon_renoteGroup]"><i class="ti ti-repeat" style="line-height: 1;"></i></div>
 		<img v-else-if="notification.type === 'test'" :class="$style.icon" :src="infoImageUrl"/>
 		<MkAvatar v-else-if="'user' in notification" :class="$style.icon" :user="notification.user" link preview/>
-		<MkAvatar v-else-if="notification.type === 'exportCompleted'" :class="$style.icon" :user="$i" link preview/>
 		<img v-else-if="'icon' in notification && notification.icon != null" :class="[$style.icon, $style.icon_app]" :src="notification.icon" alt=""/>
 		<div
 			:class="[$style.subIcon, {
@@ -27,6 +26,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				[$style.t_pollEnded]: notification.type === 'pollEnded',
 				[$style.t_achievementEarned]: notification.type === 'achievementEarned',
 				[$style.t_exportCompleted]: notification.type === 'exportCompleted',
+				[$style.t_login]: notification.type === 'login',
 				[$style.t_roleAssigned]: notification.type === 'roleAssigned' && notification.role.iconUrl == null,
 			}]"
 		>
@@ -40,6 +40,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 			<i v-else-if="notification.type === 'pollEnded'" class="ti ti-chart-arrows"></i>
 			<i v-else-if="notification.type === 'achievementEarned'" class="ti ti-medal"></i>
 			<i v-else-if="notification.type === 'exportCompleted'" class="ti ti-archive"></i>
+			<i v-else-if="notification.type === 'login'" class="ti ti-login-2"></i>
 			<template v-else-if="notification.type === 'roleAssigned'">
 				<img v-if="notification.role.iconUrl" style="height: 1.3em; vertical-align: -22%;" :src="notification.role.iconUrl" alt=""/>
 				<i v-else class="ti ti-badges"></i>
@@ -59,6 +60,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 			<span v-else-if="notification.type === 'note'">{{ i18n.ts._notification.newNote }}: <MkUserName :user="notification.note.user"/></span>
 			<span v-else-if="notification.type === 'roleAssigned'">{{ i18n.ts._notification.roleAssigned }}</span>
 			<span v-else-if="notification.type === 'achievementEarned'">{{ i18n.ts._notification.achievementEarned }}</span>
+			<span v-else-if="notification.type === 'login'">{{ i18n.ts._notification.login }}</span>
 			<span v-else-if="notification.type === 'test'">{{ i18n.ts._notification.testNotification }}</span>
 			<span v-else-if="notification.type === 'exportCompleted'">{{ i18n.tsx._notification.exportOfXCompleted({ x: exportEntityName[notification.exportedEntity] }) }}</span>
 			<MkA v-else-if="notification.type === 'follow' || notification.type === 'mention' || notification.type === 'reply' || notification.type === 'renote' || notification.type === 'quote' || notification.type === 'reaction' || notification.type === 'receiveFollowRequest' || notification.type === 'followRequestAccepted'" v-user-preview="notification.user.id" :class="$style.headerName" :to="userPage(notification.user)"><MkUserName :user="notification.user"/></MkA>
@@ -225,6 +227,7 @@ function getActualReactedUsersCount(notification: Misskey.entities.Notification)
 	--eventReactionHeart: var(--love);
 	--eventReaction: #e99a0b;
 	--eventAchievement: #cb9a11;
+	--eventLogin: #007aff;
 	--eventOther: #88a6b7;
 }
 
@@ -346,6 +349,12 @@ function getActualReactedUsersCount(notification: Misskey.entities.Notification)
 	pointer-events: none;
 }
 
+.t_login {
+	padding: 3px;
+	background: var(--eventLogin);
+	pointer-events: none;
+}
+
 .tail {
 	flex: 1;
 	min-width: 0;
diff --git a/packages/misskey-js/src/autogen/types.ts b/packages/misskey-js/src/autogen/types.ts
index 6aaeabec7..46fc2496d 100644
--- a/packages/misskey-js/src/autogen/types.ts
+++ b/packages/misskey-js/src/autogen/types.ts
@@ -4288,7 +4288,14 @@ export type components = {
       exportedEntity: 'antenna' | 'blocking' | 'clip' | 'customEmoji' | 'favorite' | 'following' | 'muting' | 'note' | 'userList';
       /** Format: id */
       fileId: string;
-    }) | ({
+    }) | {
+      /** Format: id */
+      id: string;
+      /** Format: date-time */
+      createdAt: string;
+      /** @enum {string} */
+      type: 'login';
+    } | ({
       /** Format: id */
       id: string;
       /** Format: date-time */
@@ -18550,8 +18557,8 @@ export type operations = {
           untilId?: string;
           /** @default true */
           markAsRead?: boolean;
-          includeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'app' | 'test' | 'pollVote' | 'groupInvited')[];
-          excludeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'app' | 'test' | 'pollVote' | 'groupInvited')[];
+          includeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'login' | 'app' | 'test' | 'pollVote' | 'groupInvited')[];
+          excludeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'login' | 'app' | 'test' | 'pollVote' | 'groupInvited')[];
         };
       };
     };
@@ -18618,8 +18625,8 @@ export type operations = {
           untilId?: string;
           /** @default true */
           markAsRead?: boolean;
-          includeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'app' | 'test' | 'reaction:grouped' | 'renote:grouped' | 'pollVote' | 'groupInvited')[];
-          excludeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'app' | 'test' | 'reaction:grouped' | 'renote:grouped' | 'pollVote' | 'groupInvited')[];
+          includeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'login' | 'app' | 'test' | 'reaction:grouped' | 'renote:grouped' | 'pollVote' | 'groupInvited')[];
+          excludeTypes?: ('note' | 'follow' | 'mention' | 'reply' | 'renote' | 'quote' | 'reaction' | 'pollEnded' | 'receiveFollowRequest' | 'followRequestAccepted' | 'roleAssigned' | 'achievementEarned' | 'exportCompleted' | 'login' | 'app' | 'test' | 'reaction:grouped' | 'renote:grouped' | 'pollVote' | 'groupInvited')[];
         };
       };
     };
diff --git a/packages/sw/src/scripts/create-notification.ts b/packages/sw/src/scripts/create-notification.ts
index 2b7dfd4f2..364328d4b 100644
--- a/packages/sw/src/scripts/create-notification.ts
+++ b/packages/sw/src/scripts/create-notification.ts
@@ -210,6 +210,12 @@ async function composeNotification(data: PushNotificationDataMap[keyof PushNotif
 						tag: `achievement:${data.body.achievement}`,
 					}];
 
+				case 'login':
+					return [i18n.ts._notification.login, {
+						badge: iconUrl('login-2'),
+						data,
+					}];
+
 				case 'exportCompleted': {
 					const entityName = {
 						antenna: i18n.ts.antennas,
diff --git a/packages/sw/src/types.ts b/packages/sw/src/types.ts
index fac3e707d..4f8277980 100644
--- a/packages/sw/src/types.ts
+++ b/packages/sw/src/types.ts
@@ -50,4 +50,5 @@ export type BadgeNames =
 	| 'quote'
 	| 'repeat'
 	| 'user-plus'
-	| 'users';
+	| 'users'
+	| 'login-2';