We are Exchange 2000 environment with Office XP. An outside client saved an outlook messages as (msg) Unicode Format (I suspect) and attached it to an email message and sent it to us. When we try to open the attached message we get "The messaging interface has returned an unknown error. If the problem persists restart Outlook.
Restarting Outlook doesn't work. I have Exchange 2003 with Outlook 2003 at home and was able to reproduce the error message. In Outlook 2003 there is a message format called UNICODE .msg. You can either save a message as .msg or UNICODE .msg. The error message came up when I saved an email message on my desktop using the UNICODE .msg format. I sent myself an email and attached the UNICODE .msg message to my email. When I tried to open the attachment using my Outlook at work, I received the same error message. I am not sure what the client is doing, or maybe he is using some other email client that is causing this?
500 points for an explanation/sulution.