diff --git a/dictation_server/src/features/tasks/tasks.service.ts b/dictation_server/src/features/tasks/tasks.service.ts
index 7b7c127..898a8f9 100644
--- a/dictation_server/src/features/tasks/tasks.service.ts
+++ b/dictation_server/src/features/tasks/tasks.service.ts
@@ -435,7 +435,7 @@ export class TasksService {
             `author_id not found. audioFileId: ${audioFileId}. account_id: ${user.account_id}`,
           );
         }
-        const { external_id: authorExternalId } =
+        const { external_id: authorExternalId, notification: authorNotification } =
           await this.usersRepository.findUserByAuthorId(
             context,
             task.file.author_id,
@@ -454,6 +454,7 @@ export class TasksService {
         ]);
 
         // メール送信に必要な情報を取得
+        // Author通知ON/OFF関わらずAuthor名は必要なため、情報の取得は行う
         const author = usersInfo.find((x) => x.id === authorExternalId);
         if (!author) {
           throw new Error(`author not found. id=${authorExternalId}`);
@@ -488,7 +489,7 @@ export class TasksService {
         // メール送信
         this.sendgridService.sendMailWithU117(
           context,
-          authorEmail,
+          authorNotification ? authorEmail : null,
           typistEmail,
           authorName,
           task.file.file_name.replace('.zip', ''),
diff --git a/dictation_server/src/gateways/sendgrid/sendgrid.service.ts b/dictation_server/src/gateways/sendgrid/sendgrid.service.ts
index 17fa39b..ac9a5df 100644
--- a/dictation_server/src/gateways/sendgrid/sendgrid.service.ts
+++ b/dictation_server/src/gateways/sendgrid/sendgrid.service.ts
@@ -875,7 +875,7 @@ export class SendGridService {
    */
   async sendMailWithU117(
     context: Context,
-    authorEmail: string,
+    authorEmail: string | null,
     typistEmail: string,
     authorName: string,
     fileName: string,
@@ -903,7 +903,7 @@ export class SendGridService {
       // メールを送信する
       await this.sendMail(
         context,
-        [authorEmail, typistEmail],
+        [authorEmail, typistEmail].filter((x): x is string => x !== null),    // authorEmailがnullの場合は除外する
         [],
         this.mailFrom,
         subject,