As I was already asked several times:
If you drag and drop a file from the Quickr connector in Lotus Notes into a mail, just a link to this file is created. The same is true if you select "Copy" from the context menu in the connector.This is a nice thing if the recipients of your mail have access to the Quickr place.
Copying the attachment itself into your mail is not so obvious.
To do this, you select the attachment in the connector and then choose "Edit -> Copy as attachment" in the "Edit" menu of the Notes client. Then you can just paste the attachment from the clipboard into your mail.
Caution: If you select a large document it could take some time until the attachment is available in the clipboard. You cannot paste the document to your mail before it was fully copied!