feat: establish core backend API server with S2A proxy, configuration, and mail services, alongside frontend email configuration page and toast component.

backend/cmd/main.go

@@ -355,7 +355,61 @@ func handleMailServices(w http.ResponseWriter, r *http.Request) {
 		}
 		api.Success(w, safeServices)
 	case "POST":
-		api.Error(w, http.StatusNotImplemented, "更新邮箱服务配置暂未实现")
+		var req struct {
+			Services []struct {
+				Name       string `json:"name"`
+				APIBase    string `json:"apiBase"`
+				APIToken   string `json:"apiToken"`
+				Domain     string `json:"domain"`
+				EmailPath  string `json:"emailPath"`
+				AddUserAPI string `json:"addUserApi"`
+			} `json:"services"`
+		}
+
+		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+			logger.Error(fmt.Sprintf("解析邮箱服务配置失败: %v", err), "", "mail")
+			api.Error(w, http.StatusBadRequest, "解析请求失败")
+			return
+		}
+
+		// 转换为 config.MailServiceConfig
+		var services []config.MailServiceConfig
+		for _, s := range req.Services {
+			emailPath := s.EmailPath
+			if emailPath == "" {
+				emailPath = "/api/public/emailList"
+			}
+			addUserAPI := s.AddUserAPI
+			if addUserAPI == "" {
+				addUserAPI = "/api/public/addUser"
+			}
+			services = append(services, config.MailServiceConfig{
+				Name:       s.Name,
+				APIBase:    s.APIBase,
+				APIToken:   s.APIToken,
+				Domain:     s.Domain,
+				EmailPath:  emailPath,
+				AddUserAPI: addUserAPI,
+			})
+		}
+
+		// 更新邮箱服务配置
+		mail.Init(services)
+
+		// 保存到全局配置
+		if config.Global != nil {
+			config.Global.MailServices = services
+		}
+
+		logger.Success(fmt.Sprintf("邮箱服务配置已保存: %d 个服务", len(services)), "", "mail")
+		for _, s := range services {
+			logger.Info(fmt.Sprintf("  - %s (%s) @ %s", s.Name, s.Domain, s.APIBase), "", "mail")
+		}
+
+		api.Success(w, map[string]interface{}{
+			"message": fmt.Sprintf("已保存 %d 个邮箱服务配置", len(services)),
+			"count":   len(services),
+		})
 	default:
 		api.Error(w, http.StatusMethodNotAllowed, "不支持的方法")
 	}