code: public void postUiOpenwindowNewmail(String datasource, String token, UiNewMail uiNewMail) throws ApiException {
          postUiOpenwindowNewmailWithHttpInfo(datasource, token, uiNewMail);
      }
docs: Open New Mail Window Open the New Mail window, according to settings from
  the request if applicable --- SSO Scope: esi-ui.open_window.v1
  
  @param datasource
  The server name you would like data from (optional, default to
  tranquility)
  @param token
  Access token to use if unable to set a header (optional)
  @param uiNewMail
  (optional)
  @throws ApiException
  If fail to call the API, e.g. server error or cannot
  deserialize the response body