Technically, removing the attachment does corrupt the message. The Base64 encoded part is the attachment. I've never removed any attachments. I just archive messages somewhere "On my Mac" instead. The reports are that after removing attachments, Lion gets confused until you rebuild the mailbox. Try that.
It removes the binary attachment part of the message- but that doesn't mean it removes all of the mime encoding in the message- rich text etc. is encoded and it's what it leaves behind that is corrupted.
I should have mentioned that I have rebuilt my mailbox- indeed I do it about once every hour as Lion's threading gets very confused sometimes and I have to rebuild to get it sorted.
gindaray- it doesn't seem that there's a lot of us with this problem. It would probably be very useful if we could compare set-ups to see what we have in common.
The mail account you are using that gets the corruption- is it an Exchange account? If so do you know what version of Exchange server it is using? Anything else interesting about your set-up? Are you using any addons with mail?
I have the problem, too, and have even contacted Apple about it, and held a remote session with one of Apple's senior advisors to show him the problem in real time on a repeatable basis. My last experiment was instructive, as I'm playing around with Mail.app under both Lion and Snow Leopard. I can see gibberish thru Mail.app on Lion, while all looks fine for the exact same message thru Mail.app on Snow Leopard. I, too, had originally thought this was a corruption issue; now I think it's an encoding issue.
I understand that when an attachment is removed, the message with the attachment is actually deleted, and is replaced by a new message on the server without the attachment. The Activity window in Mail.app actually shows this 2-step process.
I haven't played around after 10.4.7 last week. The full release notes for 10.4.7 didn't mention a fix for this issue. Anyone notice any improvement?
FWIW, our Exchange Server is hosted by Intermedia (http://www.intermedia.net), which, I'm told, is one of the largest Exchange hosts out there. I've not followed up with Intermedia on my own, as I think Apple really owes it to enterprise users to fix this problem itself, especially given Apple's own pull-back from the Apple-branded server market.
I raised this as bug ID 9915347 with Apple in November 2011.
It seems that the things that provoke this is removing attachments in a mail with an Asian font (I have found it happens with Korean fonts too) on a mail stored on an Exchange server.
Interesting that Snow Leopard is displaying the mails correctly. In my investigation I found that the raw message itself was being recreated correctly but the Base64 version of the mail (which is the version that contains all of the formatting etc.) is definitely corrupted. It is definitely not a display issue, it's the way that Mail.app re-encodes the rich text in Base64.
P.S. I've not yet noticed the issue in 10.7.4. Will keep an eye out.
FWIW, my reference, from about a month ago, is Express Lane Case 300149470. For those of you who call or correspond with Apple support, you'll help yourself by mentioned these 2 prior case numbers so that your tech can more quickly digest the problem and, more likely, can quickly elevate your inquiry into the upper tech support levels.
Thanks for being the guinea pig on 10.7.4, Screaming.Pict.
I noticed you cited a bug ID. I've forgotten how to do that, thought I've reported bugs in the past. Remind me (us) please? And to all who read this thread and have this problem, you'll help Apple understand and prioritize this problem if each of you report the bug yourself. Thanks.
<Email Edited by Host>
You just log in with your appleID and you get a fairly basic web interface to raise a bug report and view your existing bugs.
Like Edward says- anyone with this issue please do raise a bug (and reference the bugID I submitted) in case it gives Apple more information and a better understanding of the issue.
Update: I've been digging around for a workaround for this issue.
For now the solution I have settled on is;
1- Mail Act-On (to allow me to trigger rules, and thus scripts, on demand)
2- A script to save all the attachments in a mail (run from an Act-On rule)
3- A rule to move the mail from the Exchange mailbox into a local 'Holdiing' folder
4- I would then have written a script to remove attachments from any mail that drops into the 'Holding' folder, but Applescript doesn't let you do that, so instead I have just created a keyboard shortcut to the menu item 'Remove Attachments'
So now instead of filing messages (using a hotkey to trigger Mail-ActOn to move a message) I use a hotkey to remove the attachments and move the mail to the holding folder and once in a while I will go to the folder, remove the attachments from the messages and trigger the hotkey to file the messages.
It's 4 keystrokes instead of 1 (Save & Move, Select Holding Folder, Remove attachments, File Message) but better that than corrupted mail messages.
If anyone wants the script to save attachments let me know and I'll post it up.
Interesting. Would you mind describing the steps without Mail Act-On and scripts? I mean, how would you do this to just one email in the Entourage inbox with an attachment. For example, I'm not sure I know how to save attachments in an email.
Thanks a bunch for helping us all try to work through this shameful mess.
Edward- do you mean Entourage mailbox or Exchange mailbox? i.e. are you using mail.app or Entourage/outlook as your mail client?
Assuming you meant Exchange mailbox on mail.app, the steps you would take are simple;
1- Save attachments
In the mail, click the 'Save' button (next to the 'Quicklook' button) to save all attachments to your normal folder (this folder is changeable in the settings- the default is to save to your 'Downloads' folder).
2- Move the mail to a local mailbox.
If you don't already have a local mailbox then select Menu: Mailbox/New Mailbox... and in the dialog box select 'On my Mac' to save the mailbox locally instead of on the Exchange server.
To move the message you select menu: Message/Move to... and select the local mailbox
3- Remove attachments
View the local mailbox, select the message you moved in there and do menu: Message/Remove Attachhments
(I have added a keyboard shortcut for this as I do it a lot)
Because it's a local mailbox the message should be stripped of its attachments without corruption.
4- File the message
Now that the message has been stripped of the attachments, file the message in whatever mailbox you want with menu: Message/Move to...
Hope this helps.
Mail 6.0, Mountain Lion on Macbook Air.
I am not sure if this is the right thread, but figured I'd add here first.
When I Remove Attachments from Mail now, the attachment is in fact removed, but it is replaced with multiple .txt files which are placed at the end of the message. I then cannot remove the .txt files.
I have done a rebuild of the mailbox and I have done a re-index on the Mac, but the problem does not get resolved.
Any help would be appreciated.