Can't Forward Emails

I've been trying to forward some emails from my boss' account, and keep
getting this response:

The connection to the server has failed. Subject 'Fw: JSEI Affiliates
Volunteer Update', Account: '', Server: '', Protocol:
SMTP, Port: 25, Secure(SSL): No, Socket Error: 10060, Error Number: 0x800CCC0E

Everything was working just fine yesterday. What's going on here? And what
can I do? Thanks!