Hi
Based on test, I can't find the “Replied to timestamp”. Since the mail table stored the “DateTimeReceived” and “DateTimeSent”, you can refer to below formula to get the “DateTimeSent” as the “replied to timestamp”.
Table = FILTER(Mail, AND(ISERROR(SEARCH("Sent Items", Mail[Folder Path]))=FALSE(),ISERROR(SEARCH("RE:", Mail[Subject]))=FALSE()))
Notice: The formula is used to filter the table which “folder path” is “send items” and “subject” contains “RE:”, the “DateTimeSent” is the “replied to timestamp”.
Regards,
Xiaoxin Sheng