diff --git a/src/main/java/com/onixbyte/deltaforceguide/client/EmailClient.java b/src/main/java/com/onixbyte/deltaforceguide/client/EmailClient.java
index 52a772f..fdf9bec 100644
--- a/src/main/java/com/onixbyte/deltaforceguide/client/EmailClient.java
+++ b/src/main/java/com/onixbyte/deltaforceguide/client/EmailClient.java
@@ -26,9 +26,6 @@ public class EmailClient {
 
     private final TemplateEngine emailTemplateEngine;
 
-    @Value("${spring.mail.username}")
-    private String fromAddress;
-
     @Autowired
     public EmailClient(
             JavaMailSender mailSender,
@@ -38,6 +35,13 @@ public class EmailClient {
         this.emailTemplateEngine = emailTemplateEngine;
     }
 
+    private String fromAddress;
+
+    @Autowired
+    public void setFromAddress(@Value("${spring.mail.username}") String fromAddress) {
+        this.fromAddress = fromAddress;
+    }
+
     /**
      * Send a template-based HTML email asynchronously.
      *
diff --git a/src/main/resources/application.yaml b/src/main/resources/application.yaml
index cf3b3e8..12b0093 100644
--- a/src/main/resources/application.yaml
+++ b/src/main/resources/application.yaml
@@ -32,6 +32,10 @@ spring:
     baseline-on-migrate: true
   thymeleaf:
     enabled: false
+  mail:
+    # This configuration is used to suppressing warnings of no beans found of JavaMailSender.
+    host: example.smtp.com
+    username: app@dfguide.onixbyte.cn
 
 mybatis:
   configuration: