以管理员方式打开exchange Management Shell 管理工具
查询单封邮件发送情况，无主题查询
Get-TransportService | Get-MessageTrackingLog -sender "发件人" -Recipients "收件人" -start "8/22/2021" -end "8/24/2021" | sort-object Timestamp| fl timestamp,MessageSubject,source,eventid,SourceContext
查询单封邮件发送情况，有主题更精确查询
Get-TransportService | Get-MessageTrackingLog -sender "外部邮件地址" -Recipients "内部邮件地址" -start "8/22/2021" -end "8/24/2021" -messagesubject "主题" | sort-object Timestamp| fl timestamp,MessageSubject,source,eventid,SourceContext
官网文档介绍
https://docs.microsoft.com/zh-cn/exchange/mail-flow/transport-logs/message-tracking?view=exchserver-2016
https://docs.microsoft.com/zh-cn/powershell/module/exchange/get-messagetrackinglog?view=exchange-ps