these are Outlook 2002 info but you can check on outlook 2003 too.
1st check your email settings with below
OL2002: You Receive 0x8004210A, 0x800CCC0B, and 0x8004210B Error Messages When You Send and Receive E-Mail Message with a POP3
E-Mail Account
http://support.microsoft.com/kb/827349/en-us
if settings are correct, check below
[OL2002] POP3 Email Account timeout error 0x8004210a or 0x800ccc19
http://support.microsoft.com/kb/813518/ja
(this 813518 is japanese KB, I couldn't find english one,
anyway this kb say 'couse Norton antivirus 2003 or 2004,
disable email scan.)
If you have no luck,
check outlook log
How to turn on the Enable Mail Logging option for troubleshooting in Outlook 2003
http://support.microsoft.com/kb/831053/en-us
"samcl" <(E-Mail Removed)> wrote in message news:9D24560B-9E53-41E7-AD95-(E-Mail Removed)...
> Howdy Folks,
> Just adding my report to the fray.
> I get this error with outlook 2003 too.
> A restart of Windows sorts it out for a bit, but it's annoying. I have
> Norton firewall on, and windows SP2 firewall turned off.
> The mail server is fine (I checked webmail).
> Any ideas yet? I see this problem scattered around the place on Google and
> these boards, but no answers yet...