Re: Windows Mail

"Unknown error" can be caused by interference from an antivirus
program. Which antivirus are you running?
As a minimum, email scanning in the antivirus should be turned off,
although that may not be sufficient to eliminate all bad effects.
In a worst case scenario, your antivirus may need to be uninstalled.

Email scanning in any antivirus should be disabled, for reasons
explained here:

Gary VanderMolen, Microsoft MVP (Mail)
Microsoft MVP program:

"Jackad" <Jackad@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message news:B4AD6720-3002-4E8C-845E-252E493A5D42@xxxxxxxxxxxxxxxx
I can receive mails without problem but suddenly - from about mid-day today I
can no longer sent them. If I go to the website of my ISP, I have no trouble
sending them.
The error message I get is :
An unknown error has occurred. Subject 'Return of Card', Account: 'E-Mail do
SAPO', Server: '', Protocol: SMTP, Port: 25, Secure(SSL): No,
Error Number: 0x800CCC0B.
Any help/suggestions much appreciated !