这很奇怪，特别是因为不是所有的 n s是音译的，不在特定的位置。

That's odd, specially since not all the ns are transliterated and not at a specific position.

尝试调用 $ this-> email-> set_crlf（\r\\\
）; 。查看Exchange中的邮件详细信息，并检查内容类型和Charset / Encoding - 将原始邮件发送到此处，以便我们检查。

Try calling $this->email->set_crlf( "\r\n" ); as well. Look up the message details in Exchange and inspect the Content-Type and Charset / Encoding - post the raw thing here so we can inspect it.

我在 Microsoft知识库中发现这一点：

Microsoft Exchange使用增强字符集。 Microsoft Exchange的默认MIME
字符集是ISO 8859-1。一些网关做
不支持这个字符集发行线
的软返回的方式。当这种情况发生时，每行都以等号
终止，显示网关的线路长度支持结束的换行符。

Microsoft Exchange uses an enhanced character set. The default MIME character set for Microsoft Exchange is ISO 8859-1. Some gateways do not support the way this character set issues a soft return for line feeds. When this occurs, each line is terminated with an equal sign showing the line break where the gateway's line-length support ends.