Troubleshooting error messages that you receive when you are using OL and OE
http://support.microsoft.com/kb/813514

Disable email scanning by your anti-virus application. It provides no
additional protection and even Symantec says it's not necessary:

QP
Disabling Email Scanning does not leave you unprotected against viruses that
are distributed as email attachments. Norton AntiVirus Auto-Protect scans
incoming files as they are saved to your hard drive, including email and
email attachments. Email Scanning is just another layer on top of this. To
make sure that Auto-Protect is providing the maximum protection, keep
Auto-Protect enabled and run LiveUpdate regularly to ensure that you have
the most recent virus definitions.
/QP
http://service1.symantec.com/SUPPORT...02111812533106
--
~Robear Dyer (PA Bear)
MS MVP-IE, Mail, Security, Windows Desktop Experience - since 2002
AumHa VSOP & Admin http://aumha.net
DTS-L http://dts-l.net/

Easy T wrote:
Hi, I'm having a ptoblem with sending e-mails using Outlook Express 6.0 .
My
OS is Windows XP. I am also using Norton Virus protection which is updared
regularly.

The error message I recieve is

An unknown error has occurred. Account: 'pop.ntlworld.com', Server:
'smtp.ntlworld.com', Protocol: SMTP, Server Response: '421
aamtaout02-winn.ispmail.ntl.com connection refused from [86.27.210.20]',
Port: 25, Secure(SSL): No, Server Error: 421, Error Number: 0x800CCC67

Can anyone throw any light on this?