Anyone posting data to CWOP using the Tier 2 servers need to change your settings, as the Tier 2 servers are offline. Only the core servers are currently in service. Things may change, but that's the present status.
Russ Chadwick from NOAA posted the following message on the CWOP QC message list a little while ago:
"As of a few hours ago, the Tier 2 operators abruptly withdrew support
for CWOP traffic through their servers. We're sorry for any
inconvenience this causes CWOP members, but you will have to change the server designation in your local software. More details athttp://www.wxqa.com/news.html
Available servers at present are:
aprsfl.net : port 14580 - - - Dave, KG4YZY - - - Tampa Bay, FL (Core 3)
first.aprs.net : port 14580 - - - Gerry, N5JXS - - - College Station, TX (Core 1)
rotate.aprs.net : port 14580 - - - connects to a Core APRS-IS server and rotates to a different one if that connection drops.
second.aprs.net : port 14580 - - - Greg, WB6ZSU - - - Irvine, CA (Core 2)
The rotate.aprs.net server is probably the best choice at present.