I cannot send out going emails

[PJ]

I set up a new (2nd) email account. I am unable to send
outgoing emails and I get the following error:

The connection to the server has failed. Account: 'TTT',
Server: 'mail.lexyl.com', Protocol: SMTP, Port: 25, Secure
(SSL): No, Socket Error: 10051, Error Number: 0x800CCC0E

I use a laptop and a wireless PC card at home and a dial
up connection at the office when using.

Help. Thanks.