If you have a firewall, you will need to configure it to let Mozy through.

Mozy backs your data up by making a secure TCP connection over the Internet to the Mozy servers. This will usually trigger firewall software, which will simply ask you if you want to let it through. Since backups happen automatically throughout the day, select the option that will always allow it access.

Sometimes firewall software will not prompt you and will block Mozy by default. In that case, you will need to manually configure your firewall. The following instructions are intended to help you in this process.

This tutorial covers four different common firewalls: Norton Internet Security, McAfee Security Center, ZoneAlarm Security Suite, and Windows Security Center.

If you are an expert firewall administrator, and want the short version, here it is:

MozyConfig.exe, open outbound port 443
MozyBackup.exe, open outbound port 443

Please click on the firewall that you are using:

Norton Internet Security
McAfee Security Center
ZoneAlarm Security Suite
Windows Security Center (Windows Firewall)