How to set ICQ behind a firewall [1/2]

ICQ should be able to detect your firewall settings and use them to allow proper connection.
If you can't connect, try changing the ICQ server port as follows:
Click Main > Options. In the Options window click Connections from the Advanced list on the left.
Select Manual settings. Under ICQ Server, change the port number to 5190 or 443. Click OK and try to connect.

- If you are using a personal firewall, you will probably be asked to approve the Icqlite.exe outgoing TCP connection. You will need to approve, if you want ICQ to work properly.
You may also be asked to let Icqlite.exe, act as a server or accept connections from the internet when trying to transfer files, play games and use the Video, Push-to-Talk and Voice chat features. You will need to approve, if you want these features to work properly.

In order for ICQ 6 to perform at its best, it's suggested you open outgoing TCP port 5190. If this port is blocked and there is no option to open it, ICQ will automatically attempt to find and use other connection methods.
If ICQ does not succeed in automatically detecting a different connection method, you can try to manually configure your proxy settings in the Connection Settings dialog, that can be reached from the Login dialog, by clicking the Setup button. (If your contact list is open, click the Main Menu, select Preferences and Security and click the Connection Settings button).
Note that you may configure ICQ to connect using HTTP tunneling without using an HTTP proxy, by simply selecting HTTP from the drop down menu and leaving the Host field blank.
Note! If you choose HTTP as your proxy server you may not be able to send files or play games via ICQ.