diff --git a/src/app.service.ts b/src/app.service.ts
index 407c6ed..043a2a0 100644
--- a/src/app.service.ts
+++ b/src/app.service.ts
@@ -1,5 +1,4 @@
 import { Injectable } from '@nestjs/common';
-import { EmailService } from './email/email.service';
 
 @Injectable()
 export class AppService {
diff --git a/src/auth/guards/auth.guard.ts b/src/auth/guards/auth.guard.ts
index 837c68d..d247b04 100644
--- a/src/auth/guards/auth.guard.ts
+++ b/src/auth/guards/auth.guard.ts
@@ -29,14 +29,14 @@ export class AuthGuard implements CanActivate {
 
     if (!bearerToken)
       throw new UnauthorizedException(
-        'please provide Bearer token in Authorization header.',
+        'Please provide Bearer token in Authorization header.',
       );
 
     const token = bearerToken.split(' ')[1];
 
     if (!token)
       throw new UnauthorizedException(
-        'auth token not found in Authorization header.',
+        'Auth token not found in Authorization header.',
       );
 
     const decodedToken = decodeJwtToken(
@@ -44,9 +44,9 @@ export class AuthGuard implements CanActivate {
       this.configService.get('APP_KEY', { infer: true }),
     ) as any;
 
-    if (!decodedToken)
+    if (!decodedToken)  
       throw new UnauthorizedException(
-        'invalid auth token or token has expired, please login to get new token.',
+        'Invalid auth token or token has expired, please login to get new token.',
       );
 
     const sessionId = decodedToken?.sessionId;
@@ -55,7 +55,7 @@ export class AuthGuard implements CanActivate {
     const authSession = await this.authSessionService.get(sessionId);
 
     if (!authSession || authSession?.authTokenVersion != authTokenVersion) {
-      throw new UnauthorizedException('please login again.');
+      throw new UnauthorizedException('Please login again.');
     }
 
     request['user'] = {
diff --git a/src/messenger/messenger.service.ts b/src/messenger/messenger.service.ts
index 9c2aa67..b92e582 100644
--- a/src/messenger/messenger.service.ts
+++ b/src/messenger/messenger.service.ts
@@ -37,7 +37,7 @@ export class MessengerService {
 
     if (!onlyOne) {
       throw new BadRequestException(
-        "only provide value for either 'send_at' or 'send_after', not both.",
+        "Only provide value for either 'send_at' or 'send_after', not both.",
       );
     }
 
@@ -64,7 +64,7 @@ export class MessengerService {
 
     if (!savedMessage) {
       throw new UnprocessableEntityException(
-        'failed to create message. please try again.',
+        'Failed to create message. Please try again.',
       );
     }
 
@@ -82,7 +82,7 @@ export class MessengerService {
 
     if (!job) {
       throw new UnprocessableEntityException(
-        'failed to add message. please try again',
+        'Failed to add message. Please try again',
       );
     }
 
@@ -98,7 +98,7 @@ export class MessengerService {
       });
 
       if (!message) {
-        throw new NotFoundException('message with id not found.');
+        throw new NotFoundException('Message with id not found.');
       }
 
       const user = await this.userRepository.findOneBy({
@@ -106,7 +106,7 @@ export class MessengerService {
       });
 
       if (!user) {
-        throw new NotFoundException('user not found.');
+        throw new NotFoundException('User not found.');
       }
 
       const recipientEmail = user.email;
diff --git a/src/user/user.service.ts b/src/user/user.service.ts
index bdd6682..216f5ec 100644
--- a/src/user/user.service.ts
+++ b/src/user/user.service.ts
@@ -22,7 +22,7 @@ export class UserService {
     });
 
     if (existingUser) {
-      throw new BadRequestException('user with this email already exists.');
+      throw new BadRequestException('User with this email already exists.');
     }
 
     const user = new User();
@@ -35,7 +35,7 @@ export class UserService {
 
     if (!saved) {
       throw new UnprocessableEntityException(
-        'failed to add user. please try again.',
+        'Failed to add user. Please try again.',
       );
     }