User Agent: Mozilla/5.0 (Windows NT 6.0; rv:38.0) Gecko/20100101 Firefox/38.0 Build ID: 20150525141253 Steps to reproduce: Emails are downloadloaded correctly. If I right click on folder, select 'Properties' and click on 'Repair Folder' Actual results: Several emails suddenly display a 'paperclip' attachment icon in the Message List. When I select to view any of those emails, the paperclip icon adjacent to message in Message list is removed. Note these emails do not have any attachments. There is no 'attachment'/paper clip in the actual email as shown in Message Pane, tab or window. Expected results: Upon 'Repair folder', emails with no attachments should not display an attachment icon. When looking at the source code I noticed a common theme. every email with a false paperclip icon has this: Content-Type: multipart/mixed; followed by a boundary line eg: boundary="GNH0X2rPFGje=_GBgfxYuM8sHpSqQsSvoy" This sounds similar to bug 479017 however, I'm not receiving them with paperclip. this only occurs if I 'Repair folder'. I'm using Vista and TB version 38.0.1

You might want to try this extension, which doesn't set a false icon without making sure: http://attachmentcount.mozdev.org/

This issue manifests in several ways. Bug bug 479017 and bienvenu's bug 241203 comment 40 describes sime issues. And iirc rsx11m also understands this area pretty well It would be very cool if someone triaged all these bugs :) http://mzl.la/1JGvIdv http://mzl.la/1JGviDP (a much more restriced list)

also, picking one (presumably old) key bug that describes this, and duping the myriad of bugs currently closed INVALID to it will make it easier for future triagers to mark other bugs as duplicate to the "correct bug"

I see exactly the opposite. Thunderbird (38.2, ubuntu linux) fails to show the paper clip for messages that have attachments until the message is opened. If I repair the folder, the paper clip disappears again. Apparently a bug about the paper clip not showing until the message is loaded has already been fixed in the past. Now it has reappeared (see 241203).

I can reproduce this: Use a message from bug 479017, that is, multipart/mixed but with no attachment. The paper clip shows at first but vanishes when the message is loaded/displayed. It returns when the folder is repaired. We should keep in mind that the messages from bug 479017 really have an invalid MIME structure. Sergio, maybe you can attach a message where you see the opposite. Or better attach it to bug 1200262.