Can receive but cannot send emails

[Doreen]

My company domain email was changed recently and now I can receive emails but
no outgoing mails are succeeding. I get an error message:
An unknown error has occurred... Protocol: SMTP, Port: 25, Secure(SSL):
No, Error Number: 0x800CCC0B

Please help

 

[Poncho25]

This could be because of a number of reasons, sending out e-mail uses port
25, so 1, either its turned off on the surver for some reason. (good way to
check, is to see if anyone else is unable to send) or 2. You have an
anti-virus device that re-routes the e-mail to a dif port other then port 25.
Turn off your anti virus and try sending, if that works then you will have to
figure out how to change the port settings in the software to allow port 25
to be open.

Todd

 

[Doreen]

Well everybody else here seems to be able to send and my anti virus is
expired so it is not working. Could it be something else different?