Mail 2.0: A 100%-reproducible way to make e-mail messages disappear altogether

Posted by Pierre Igot in: Mail
January 19th, 2006 • 2:34 pm

This is very bad.

Over the past few months, I have lost a few vital messages, which somehow have disappeared completely from my system.

Today, it happened again, right in front of my eyes. I had selected a message in my Inbox and dragged it to a mailbox to archive it, and dropped it on the wrong mailbox, and clicked on things in a certain way and undone the move at the same time, and boom—the message was gone. It was no longer in my Inbox. It was not in the wrong mailbox where I had dropped it. And it was not in the right destination either.

I tried to do a search in all mailboxes for the message. It was nowhere to be found. I tried with the system-wide Spotlight search. No results. The message should have been easy to find, because it was the first one I had received from a store where I had never bought anything before. So it was the first one with that store’s e-mail address for order confirmations.

But the message had disappeared from my system altogether. It was not in the Trash. It was not in the Junk mailbox. I tried rebuilding the mailboxes involved, in case the message was somehow still there but not shown in the message list. But nothing was able to bring it back. It was gone.

Since it had just happened and I more or less remember the exact steps I had followed, I tried to reproduce it. It took me a little while, but I finally found it. Here’s the 100%-reproducible sequence that can cause your message to compeletely disappear from Mail, with no chance of recovery.

In order to reproduce this, you need to have at least two mailbox folders in your mailbox drawer (not smart mailboxes, real static mailboxes where you can drag and drop messages to archive them). Then all you need to do is the following. (Don’t try this with an important message. It will be gone!) Say the two mailboxes in your mailbox drawer are Mailbox A and Mailbox B.

  1. Select your Inbox in the mailbox drawer.
  2. Select a message in the message list.
  3. Take the message and drag it to Mailbox A. Do not release the mouse button yet. Just hold your mouse button down with the message ready to be dropped onto the Mailbox A icon in the mailbox drawer.
  4. Now comes the tricky part: As soon as you release your mouse button, you will need to click once on Mailbox B in the mailbox drawer. It is absolutely crucial that do these two things in very rapid succession. If you drop the message on Mailbox A and wait before your click on Mailbox B, nothing bad will happen. You absolutely need to click on Mailbox B while Mail is still in the process of moving the message to Mailbox A, which takes only a fraction of a second. So you need to be fast.
  5. Once you’ve clicked on Mailbox B, press command-Z or select the “Undo” command in the “Edit” menu. If you didn’t do step 4 quickly enough, this won’t work. The “Undo” command will be greyed out and unavailable, because Mail forgets the last move command you effected as soon as you click on another mailbox in the mailbox drawer. But if you clicked on Mailbox B fast enough in step 4, while Mail was still in the process of moving the message to Mailbox A, then the “Undo” command will be available, and Mail will let you undo the last action, i.e. the action that moved your message from the Inbox to Mailbox A.
  6. Now, click on your Inbox, and look for your message in the list. It should be back there, shouldn’t it? You’ve just undone the move. But the message is not there. Click on Mailbox A. It’s not there either. It’s gone! It has disappeared altogether! (It’s not in Mailbox B either, of course.)

After this happened to me again earlier today, I sent myself a bunch of test messages, and I tried to reproduce the problem. With the steps above, as long as step 4 is done fast enough, with no delay between the time you release the mouse button to drop the message on Mailbox A and the time you click on Mailbox B, you should be able to reproduce this on your machine too. This is happening to me with Mail 2.0.5 on a Power Mac G5 Quad, which is pretty much the fastest Mac you can get right now. So if it can happen on my machine, it can happen on yours!

And it happens to me not just when I try to reproduce the problem deliberately. It happens to me when I drop and click accidentally on the wrong mailbox, and then press command-Z! Because of this bug, I have lost several important messages, that have completely disappeared!

I should note, however, that I am only able to reproduce the problem with some of my accounts. Depending on which of my accounts the message in question was sent to, undoing the move does sometimes put the message back in the Inbox. It works as expected with some accounts, but not other accounts. I can reliably reproduce the problem with my .Mac account used as a POP account, for example.

It is really quite unacceptable. There is no excuse for it. It’s quite obvious that it’s a problem related to Mail’s multithreading capabilities. Mail can move a message in one thread and let you select another mailbox in another thread at the same time. But this screws up its “Undo” sequence completely, and Mail clearly forgets where to put the message back when you undo the action! So it just lets the message vanish altogether!

Data integrity is always paramount. We can live with bugs that make simple actions more complex than they should be, or force us to go through workarounds to achieve what we want to achieve. But bugs that destroy our data with no chance of recovery are simply bad. They are the worst kind.

If you are a Mail user, consider yourself warned!

8 Responses to “Mail 2.0: A 100%-reproducible way to make e-mail messages disappear altogether”

  1. JMTee says:

    Could this be the reason…?

    My mother lost the whole contents of her Inbox when trying to set up an archvie Mailbox for important mails according to my instructions. The process she went through included (at least) creating a new Mailbox folder, apparently selecting the whole contents of the Inbox, ‘clicking in the wrong place’ as she says, mails disappearing from the Inbox and then, at some point, trying to undo the action(s).

    I’ve not been able to get my hands on the computer yet, but we’ve tried several things via phone. It appears that the mails have really disappeared altogether. She swears she had not erased the deleted messages – or even emptied the Trash – at any point during this ordeal.

    Fortunately she was able to retrieve part of the important mails through a webmail of the service provider, but still lots of valuable stuff disappeared.

  2. Pierre Igot says:

    Could very well be the same problem. Clicking in the wrong place at the wrong time + using Undo = danger, obviously.

    As far as I can tell, there is no way to recover messages lost this way.

  3. Hawk Wings » Blog Archive » A 100% reliable way to destroy messages says:

    […] Take a read of his whole post. Or his whole blog. There’s a lot to learn there. Apple Mail’s most eagle-eyed critic doesn’t miss much. […]

  4. Paul Ingraham says:

    Thanks for the heads up on this on, Pierre.

    Actually, I feel quite suspicious that there are other data loss bugs in Mail as well, sadly. Certainly I have had several cases of being unable to find messages that just have to be there. Even allowing for some senility on my part, I still believe I have lost messages — and since my workflow doesn’t involve dragging messages around the way you do, there may be something else going on. Now I just have to prove it.

    We must stay vigilant!

  5. Paul Ingraham says:

    Okay, I have confirmed that I have also suffered from a data loss bug in Mail, and probably not the same one, judging from the differences in our workflow.

    As mentioned in my previous comment, I have been suspicious about this for a while, but it can be difficult to be certain that a given message is truly gone, given the enormous volumes of email that we all deal with. Today, however, I am unable to find a recent message that I remember composing, and the existence of which is contextually obvious (i.e. it is quote in subsequent messages, it’s receipt was explicitly confirmed in subsequent messages, etc). And an exhaustive search for it by various methods has come up empty. Finally, since deletion of messages simply is not part of my work flow in any way, it seems unlikely that I accidentally deleted it.

    It’s just gone. :( And, naturally, it was actually important.

  6. Pierre Igot says:

    Unfortunately, if you can’t reproduce the problem reliably, it’s going to be hard to get Apple to do anything about it.

  7. Paul Ingraham says:

    No kidding! It’s hard to get Apple to do anything about a bug even when you report a one that you can reproduce… like the font smoothing bug in Pages!

    However, even if I can’t reproduce it, discussing it here at might lead to other users investigating similar suspicions. If there really is another data loss bug in Mail (in addition to the one that you have confirmed), the more we compare notes the sooner we will be able to reproduce and report it, and the sooner it can be ignored by Apple for three major verisons. :)

  8. Pierre Igot says:

    Yes, we definitely need to investigate these kinds of issues as much as we can. It’s discouraging that Apple is seemingly doing so little to address them, but at least we can do our part to try and better circumscribe them.

    However, the only problem that I am able to reproduce reliably so far is the scenario discussed above.

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