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

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. :)

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.

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!

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

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.