Windows Live Mail Error ID: 0x800CCC0D and Socket error 10060

Server: ‘smtp.att.yahoo.com’

Live Mail Error ID: 0x800CCC0E

Protocol: SMTP

Port:  25

Secure (SSL): No

Socket Error:  10060

When I send a message, the message goes to the 'Outbox' but then I get the above error message and the message just sits in the Outbox and will go no further.  This has been happening for a couple of weeks but was working fine before then.  No known changes in the program or system.

I use Windows 7 Premium.

Would appreciate any help possible.