I'm using Mail with a gmail IMAP account. Recently a friend sent me an email with an Excel workbook attached, but the attachment didn't show up in Mail (no attachment in the message, no paperclip icon indicating an attachment in the Inbox). The really strange part is that if I go into my gmail account using a browser, the attachment is there. I received several other similar attachments from other people, and all those attachments showed up in Mail. Has anyone had this happen before? Any idea what might be causing it?