SingleSendMailRequest Invalid URI: The Uri string is too long.

[personball]

发送邮件sdk缺陷
涉及sdk
aliyun-net-sdk-dm
aliyun-net-sdk-core

https://github.com/aliyun/aliyun-openapi-net-sdk/blob/master/aliyun-net-sdk-dm/Dm/Model/V20170622/SingleSendMailRequest.cs#L80

htmlBody 请不要拼接到querystring里，复现方法：使用50KB以上的邮件正文，会报 uri too long.