TCP 135 and the loss of end-to-end. I've never spent much time tethered to an Exchange Server, other than on an experimental basis, so I'd forgotten — or never knew — that Outlook contacts Exchange on TCP port 135. That is, of course, the same port that Blaster has lately been partying on with wild abandon. I'd also heard that some ISPs had begun blocking 135, on the grounds that it's more trouble than it's worth. As this document from Cox High Speed Internet notes: … [Jon's Radio]