无法使用nodemailler发送pdf附件

Question

我正在使用nodemailer发送带有pdf附件的电子邮件，电子邮件已成功发送，但是通过电子邮件下载时pdf附件损坏。以下是我的mailOptions：

let mailOptions = {
        from: 'writingtest@email.xxx.com', // sender address mailfrom must be same with the user
        to: receiveEmail, // list of receivers,use , to split
        cc:'service@xxx.com', // copy for receivers
        subject: 'writing test from xxx.com', // Subject line
        text: 'Hello world', // plaintext body
        replyTo: 'service@xxx.com', //send reply email address
        attachments: [
            {
                filename: 'test.pdf',
                filePath: '../../files/test.pdf',
                contentType: 'application/pdf',
            }
        ],
    };

从回调收到的信息是：

message sent: 250 Data Ok: queued as freedom ###envid=19950767140