The problem is that after you detach an attachment, when you then forward the message, a 'stub' of the attachment is attached to the message. This causes the receiver to think there is an attachment but attachment is not actually there. To reproduce: - Send yourself an email with an attachment - Detach attachment from received message - Forward received message (to yourself or other account) - Note received message indicates it has an attachment - Note attachment is NOT the actual original attachment, rather just the MIME stub: Content-Type: application/octet-stream; name="Doonsbury.gif" Content-Description: Doonsbury.gif Content-Disposition: attachment; filename="Doonsbury.gif"; size=215295; creation-date="Tue, 09 Mar 2010 15:07:55 GMT"; modification-date="Tue, 09 Mar 2010 15:07:55 GMT" Content-Transfer-Encoding: base64 When you detach an attachment, subsequent forwarding of the message should not indicated the attachment...

See bug 327302, asking for a detached attachment to be reattached though.

(In reply to comment #1) > See bug 327302, asking for a detached attachment to be reattached though. I would even say it's a dup.

Marking as a duplicate is not a true way to resolve a bug when nothing has been done for the original !