feat: IMAP 支持 SSL/STARTTLS 配置

config.yaml.example

@@ -3,6 +3,7 @@ email_accounts:
     imap_port: 993
     username: "your_email@gmail.com"
     password: "your_app_password"
+    use_ssl: true
     smtp:
       server: "smtp.gmail.com"
       port: 465
@@ -12,6 +13,7 @@ email_accounts:
     imap_port: 993
     username: "your_email@126.com"
     password: "your_auth_code"
+    use_ssl: true
     smtp:
       server: "smtp.126.com"
       port: 465