Cable & Wireless, Verio and/or Level 3 port blocking?

["William Devine, II" <william () smartguys net>]

Can anyone from these three carriers tell me if you're doing port blocking
on the Windows file/print ports (135-139, 445 & 593) ?
A client of ours (in the US), against our recommendation, still wants to
connect to their Exchange server in the UK without a VPN.  We're not
blocking their IP#'s from anything but somewhere in between it's getting
blocked.  We use C&W directly and Verio/Level3 through a peer.

Thanks!
william