I have recently been playing with the EWS SOAP API and it seems that whilst there is the *IsRead* property that can indicates if a mailbox item has been read, there is no datetime associated with this flag. Is that correct? 

If it is not accessible via EWS, is that date stored anywhere by the exchange server?

Thanks

John

No unfortunately they don't keep a date/time on when the message was read.  Only value you can look at is the Last Modified date but obviously they could mean several things.