If you’re experiencing a problem because you are connecting through a firewall or proxy server, you will need to configure your firewall or proxy server. The following information should assist with your configuration:

Basic Connection:

Protocol: TCP or HTTP

Servers:

scs.msg.yahoo.com
scsa.msg.yahoo.com
scsb.msg.yahoo.com
scsc.msg.yahoo.com

Port: 20, 23, 25, 80, 119, 5050, 8001, 8002

Webcam Connection:

Protocol: TCP

Server: webcam.yahoo.com

Port: 5100

File Transfer Connection:

Protocol: HTTP

Server: filetransfer.msg.yahoo.com

Port: 80

File Sharing Connection:

Protocol: HTTP

Port: 80

Voice Chat Connection:

Protocol: UDP or TCP

Servers:
v1.vc.scd.yahoo.com
v2.vc.scd.yahoo.com
v3.vc.scd.yahoo.com
v4.vc.scd.yahoo.com
v5.vc.scd.yahoo.com
v6.vc.scd.yahoo.com
v7.vc.scd.yahoo.com
v8.vc.scd.yahoo.com
v9.vc.scd.yahoo.com
v10.vc.scd.yahoo.com
v11.vc.scd.yahoo.com
v13.vc.sc5.yahoo.com
vc1.vip.scd.yahoo.com

Ports: 5000-5010