Error 80042109 on sending mails

From few days my Outlook is not working at all. I am getting Error 80042109 while sending mails. It says that it is not able to connect to outgoing smtp server. I had kept my firewall on. So does it is responsible for the same. I also had Norton installed in my system. Everything was working fine, suddenly it stopped working. I hope I can locate changes or modification that are done may be during recent updates.

Yes that can be a firewall issue. It is blocking outgoing connection. If you have a antivirus installed in your system then why are you using firewall. You can disable that. The antivirus a internal firewall which is capable of blocking threats.