If you save a draft of the message, the attachment is shown in the Reading pane while in the Drafts folder. You can select the attachments from there. Further, if you are composing a message in a different window, you can preview the attachments in the draft while the...
Your DSM mailbox might be having difficulty opening if you have a slow internet speed and the server times out before all the messages load. Try again when you have a faster internet speed. If you have alot of messages in your folders the server may time out before...