Open Radar

 
Summary:
When moving or copying a message containing a 143 KB or larger PDF attachment (but not a 117 KB PDF attachment) from the Inbox to another folder on an Outlook.com IMAP account, the attachment is replaced by a "MS-Blob-Excluded" line and lost.

Steps to Reproduce:
1. Set up Mail with an Outlook.com IMAP account (imap-mail.outlook.com).
2. Create a message addressed to the Outlook.com account.
3. Attach a ≥143K PDF (one is included in the attachments to this bug).
4. Send the message.
5. Create a mailbox on the IMAP server.
6. Get mail if necessary, such that the message appears in the Inbox.
7. Open the message; double-click or Quick Look the PDF; note that it's visible.  (I have attached such a message as "before.eml".)
8. Move or copy the message by dragging from the Inbox to the new mailbox.
9. Click on the new mailbox.
10. Get mail if necessary to update the mailbox.
11. Open the moved/copied message in the new mailbox; double-click or Quick Look the attached PDF.

Expected Results:
The PDF is displayed.

Actual Results:
An empty file.  (I have attached the corresponding message as "after.eml.")  A MS-Blob-Excluded: header has been added and the body of the MIME part is missing.

Version:
Mail 7.1/1827
OS X 10.9.1/13B42

Notes:


Configuration:
I tested moving/copying the same message with a third-party IMAP client (MailMate) and the attachment was intact.

I tested with larger PDFs, up to ~3 MB, which also exhibited the problem.

I tested with a smaller PDF (the first page of the attached PDF, which is about 117 KB) and the problem did *not* occur.

The Outlook.com Web site still reports that the attachment is present in the new mailbox with its original size, however clicking on the attachment on the Web site also results in an empty file being downloaded.