我一直在查看电子邮件标题,我注意到用Microsoft Outlook发送的电子邮件中可以看到发件人的IP地址。Received: from -redacted hostname- (c-redactedipaddress-.hsd1.ca.comcast.net. [-redactedipaddress-]) by mx.google.com with ESMTPSA id -redacted- for <multiple recipients> (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits