最近由此配置Evolution，一开始网络是断开的，结果发送/接受始终为灰，重启也木有用。。。
查找了一下。这个其实很简单，但着实困扰了一阵子。后来查找evolution的帮助（Evolution常见问题）找到了。
Why is the "Send & Receive" button not working?
If the Send & Receive button is greyed out then you may be offline. To go online, click "File > Work online" and you should now be able to click the Send & Receive button.
意思就是说去点一下菜单-联机工作，就OK了。