No.

Unfortunately, Outlook Express doesn't provide any means to remove an attachment from a
sent or received message.  There are several workarounds:
1 - Forward the message to yourself, but delete the attachments from the composition
window (right click on the attachment icon) before sending.  However, this will alter the
sender's name and the date/time received.
2 - If you are familiar with the way attachments are encoded in a mail message, you can
manually edit the message source.
- Do a File, Save As to save the message to an *.EML file, or drag-and-drop the message
to a Windows folder
- Then edit the file in Notepad or other text editor.  For some information on the
formatting of attachments, see http://pages.prodigy.net/michael_santovec/decode.htm
- Save the file
- With OE5+, you can drag-and-drop the message back to an OE folder.  With OE4, you must
double click the saved file from the Windows File Explorer.  It will open in a mail
window.  You can then select File, Copy to folder.
- You can then delete the original message.
3 - Another option is the DBXtend program, which can remove attachments
http://www.oehelp.com/DBXtend/Default.aspx