I can’t send out emails using Outlook Express

Hey guys…
I am trying to get my problem resolved ASAP. I have been using Outlook Express for the longest time and never has it failed me until now. I can’t seem to send and receive messages for the last hour. I have been trying to figure things out on my own. I tried to log-in to my webmail account that I have configured for my Outlook Express, and surprisingly it works. I haven’t changed anything during the past few days. Haven’t made any changes in the system or network as well. We have 2 PC’s at home and both are hardwired and this is the only one with Outlook Express. Help please.
