Can't send or receive email in Windows Live Mail

Hi

I have switched Windows Live Mail to "Working Offline" in order to back up emails. After finishing the backup, I turned the program to "Work Online" again, but am now unable to send or receive messages.

There is no error message, the program is just stuck in "Executing" of the message sending task and won't budge.

I have tried quitting the program and starting again, have even tried rebooting the computer and the Internet connection.

I am running Windows 7.

Any suggestions?

Thank you