A quick recap, if I may;_
Symptoms are
1) Internet browsing and email are OK when using an Ethernet connection on
the machine, in Win ME
2) Internet browsing is OK,
3) email is fubarred using a wireless Network card on the same machine in
ME. - whether using OE or Thunderbird
1) just about rules out Winsock problems and proxies - but not
firewalls
or misdirections of some kind
2) pretty much rules out hardware problems unless it's either the wireless
side of the router, or the wireless card
3) just about rules it out of being an IE/OE problem
Therefore is almost certainly a software problem between the output from
OE/TB and the modem, which would imply that it's either a firewall problem
or a misconfiguration of the router or card - and I would be inclined to
believe the latter.
Power down and remove the card
Boot to Safe Mode, and open Device Manager
Remove ALL devices relating to the Wireless network card
Remove ALL entries in the 'Other devices' branch if present
Remove ALL flagged entries
Reboot to Normal Mode
Close Device Manager and Uninstall the control software for the card
Shut down, then reinstall the card per manufacturer's instructions
(Did you ever have Norton or ZoneAlarm installed on this PC? - both are
renowned for causing problems after uninstalling)

Signature
Noel Paton (MS-MVP 2002-2006, Windows)
Nil Carborundum Illegitemi
http://www.crashfixpc.com/millsrpch.htm
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Please read http://dts-l.org/goodpost.htm on how to post messages to NG's
> Mart,
>
[quoted text clipped - 10 lines]
>
> Andy