Answer
Keep in mind that connect senders and the report formatter run as server-side processes on the Middleware/Application Server host itself, not on the end user's desktop — so any file path you specify in Attach Files needs to resolve correctly from that MWS host's own filesystem perspective, not the user's local machine. A path like C:\Test\Test.pdf only works if that file genuinely exists at that exact path ON the MWS/Application Server host. UNC network paths also work, as long as the account the MWS service runs under has actual access to that network location — if it doesn't, you'll see an access-denied-style error in the resulting application message under the notification queue rather than the email silently succeeding.