I just noticed under the sorting category list there is an option to sort by date sent which is not rational. And your colleague from Microsoft team agreed with me.
https://answers.microsoft.com/en-us/msoffice/forum/msofficeoutlook-msomac-mso_o365b/date-received-vs-date-sent/7cdfd020-4e3d-4588-81a3-a37719ebd651?messageId=a288262c-484b-42af-8885-5b5078349906&tm=1586283080412