Quickmail drafts do not retain attachments

When one creates a draft email in Quickmail, it can be saved as a draft for later editing and sending. 

If one attaches a draft then saves a draft, that attachment is not retained when the user goes back to Edit and send the Quickmail draft.

Is this a bug, or just an oversight in the programming?  

Process:

Create a new Quickmail

Fill in subject line, content and attach a file.

Save as draft.

Return to draft and click Edit.

Attachment field is empty.