Our environment is Exchange Server 2013 CU3 and Outlook 2013 in cached mode. We have a transport rule that sets the max attachment size to 20 mb. If someone sends an attachment larger than 20 mb they receive an NDR letting them know the message wasn't delivered because it exceeded the max attachment size. We would like for the user to be prevented from sending the message at all or to at least get a mail tip before they try to send the message. The Outlook pop-up message that says "The file you're attaching is bigger than the server allows. Try putting the file in a shared location ..." isn't being generated for us. Not sure if that's because we're running Exchange or not. If that pop-up isn't going to work it would be nice if the user could at least get a mail-tip warning them that the attachment exceeds the limit. But it doesn't look likes there's a mail-tip for attachment size, only for message size. And, I've found that the message size mail-tip only works if the limit is set on the user. It doesn't seem to work if the limit is set via a transport rule.
Has anyone else gotten Outlook to present the pop-up or a mail-tip when exceeding attachment size? Any help you can offer would be greatly appreciated.