(i) inline attachment is a native but proprietary Notes feature that allows the Notes recipients to get the exact and intended layout of attachments of the sender in the mail body after the course of mail delivery; and
(ii) such inline attachments, because of its proprietary nature, will lose their location information when the email is sent to a public domain leaving Domino boundary, and the attachments will only remain in some order in the Attachment Section, in which the order may not be too trivial to a recipient in public domain.
After rounds of testing, we observed that, upon a reply/forward action, Notes client will user the original email to construct the history part in a new email, and the attachments in the original email will be reordered following a Z-order, which adds the left-top-most attachment in the original email to the first position in Attachment Section and append the right-bottom-most attachment as the last one. For each new attachment the Notes sender is going to insert in to the mail body, Notes client will append the list as the last item in the Attachment Section. In case this sender does not add new attachment and may just want to forward the original email for other's reference, the order of attachments appearing in this recipient in public domain will be in the opposite direction along the Attachment Section as compared to the original email, i.e. the latest attachment in the original email appears at the back in the Attachment Section, and the same attachment in the forwarded email will appear at the front in the Attachment Section.
In view of the nuisance caused by this Z-order mechanism to our users in public domain, we propose to have a switch to turn off such behavior.
To reproduce the case, please follow my steps described below,
(a) Create a new email at Notes client of User A with two attachments 1.docx and 2.docx. The focus should be on the order of the attachments, so I use (1-2) to indicate the order of the attachment, given that I insert 1.docx first from left and 2.docx the next at the same line after 1.docx;
(b) Send the email to User B, B should see the two attachments in (1-2) order in Attachment Section, assuming B is an external user and the email copy to B loses all the inline/position informtion of the attachments; B can only rely on the attachment order for the latest attachment being attached;
(c) Make a forward action upon the email in (a); add attachment 3.docx and 4.docx; send the email to B;
(d) B should receive the email with attachments in order (1-2)-(3-4), where brackets indicates the attachments are included in two time points along the email history;
(e) Repeat and make a forward action upon the email in (c); you should notice that the order of the attachment should be now (3-4-1-2) because of our observed Z-order rule;
(f) Add attachments 5.docx and 6.docx and send the email to B;
(g) B should receive the email with attachment order (3-4-1-2)-(5-6); 3. Imagine if A did not add any attachments in step (f) and just wanted to forward the email to B for the recipient reference, B should see the latest attachment 4.docx on the right at step (d), and on the left at step (g). B will be confused when to see the leftmost attachment or rightmost attachment for the latest document.
As the "inline" property of attachments will lose when leaving Domino/Notes environment, public domain recipients may only rely on the order of the attachments in MIME section to know the intended attachments from the immediate sender. If the Notes client performs reordering of attachment in each round of correspondence, no chronological order can be traced in the history of email, and the public domain user will just suffer.