[Evolution] Can't send using Evolution

[Peter James <pfjames clara co uk>]

Andre wrote
"if it isn't confidential data, could you post the header?

perhaps you took a recipient from your addressbook without an email
address, or you did not put a recipient into the To:, but only into the
CC-field...
are there any other emails in your outbox? sometimes evolution refers to
another message and does not at first send the message which is "on top"
in your outbox, and stops sending other messages if one of them could
not be sent.

...normally evolution really got a reason to show this error
message. :-)"

The header of a failed Email is as follows:

From:   Peter James <pfjames clara co uk>
Reply-To:       pfj pfjames clara co uk
To:     Alan Menzies <wingfeld btopenworld com>
Subject:        Changing to a PC from a Mac
Date:   Tue, 29 Jun 2004 16:18:31 +0100 
xxxxxxxx   
xxxxxxxx
xxxxxxxx
etc etc

I have attempted to send this email three times, without success.  I have also 
cleared out of my Outbox all previous emails that failed to send.  I am at my 
wits end here.  Can anyone help?

Peter James