[carlingman]

Alternatively it could be the mail is getting stuck somewhere on the server and failing to delete.

You could then try this -

Telnet it and bin it completely.

To telnet it try the following -

To telnet the mail server:
Click onto Start then Run
type telnet pop.ntlworld.com 110 - press enter
+OK InterMail POP3 server ready.
type user then a space then your user.name - press enter
+OK please send PASS command
type pass then a space then your password - press enter
+OK user.name is welcome here

This logs you into the pop server.

type list.

Identify the mail you think is causing the problem and type DELE 1 or whichever number corresponds.

Then type quit to close the telnet connection.

That should then bin the offending mail.

Go back to outlook express and try redownloading send/receive.

Hopefully then no more duplicate mails.