Change to Autowire in constructor

application/module-mail/src/main/java/org/fuseri/modulemail/service/MailService.java

@@ -8,8 +8,12 @@ import org.springframework.mail.javamail.JavaMailSender;
 @Service
 public class MailService {
 
+    private final JavaMailSender emailSender;
+
     @Autowired
-    private JavaMailSender emailSender;
+    public MailService(JavaMailSender emailSender) {
+        this.emailSender = emailSender;
+    }
 
     public String send(MailDto dto) {
         var message = new SimpleMailMessage();