目前网上很多地方流传的以下命令语法在2016/2019中证实已经不起作用：
Search-Mailbox -Identity UserName -SearchQuery “sent:<2016/12/16”-deletecontent Search-Mailbox -Identity UserName -SearchQuery “sent:=2016/12/16”-deletecontent Search-Mailbox -Identity UserName -SearchQuery “sent:>2016/12/16”-deletecontent
Search-Mailbox -Identity UserName -SearchQuery “sent:<2016/12/11 and 2016/12/16” –deletecontent
该命令不会报错，只是没有结果：
经过艰难测试，证实以下新的命令可以实现预期效果：
Search-Mailbox -Identity UserName -SearchQuery {sent:01/01/2019..09/23/2019} -DeleteContent
Search-Mailbox -Identity UserName -SearchQuery {received:01/01/2019..09/23/2019} -DeleteContent
