Mail.app corrupting attachments

I am having the same problem on my iMac but not a gmail account, standard IMAP account with a local ISP. I can view the same message on my MacBook Pro no problem but on the iMac the attachments are corrupt. I can also log into webmail and see the message with attchemnts intact.

I'm thinking disk problem but will keep digging.

Just thought I'd chime in as I doubt this has anything to do with the serivce that is handling email.

Just rebuild your mailbox.

Rebuilding my Mailboxes (1 at a time) worked.

FYI, I have an IMAP acct from a major hosting company. No Gmail, No ISP email. Running Lion 10.7.3 on an iMac.

I inadvertently found the answer to this problem when I repaired another problem, that my software update wouldn't connect, nor would other non-apple apps. I posted on the forums and was directed to check for and uncheck any proxys in preferences/network/advanced/proxies. Deselecting anything here re-enabled my software update and Mail app suddenly stopped blocking images. Your mileage may vary.

Hey Mail.app is corrupting my attachments as well. I have to Gmail acoounts and it seems to corrupt the file attachments form one account only. I just don't get it... It was working fine before 10.7.4

It's not 'complete and utter nonsense'. I have the same issue.

And rebuild mailbox didn't work.

BTW, I don't use gmail but me.com and a couple of other servers, so it can happen in the best families 😀

I have the same problem.

mail.app corrupts both in-bound and out-bound attachments. Rebuilding the mailbox helps, but I have to rebuild the mailbox for each message with an attachment. This is running against our company mail server, and the problem occurs only on my mac with Lion. My older laptop running 10.6.8 is fine.

I'm having the same problem. It wasn't noticeable initially as it seems to affect only 1 client of mine. Soon after it start to spread to others and internally. All attachments will be received as corrupted when it reaches our recepients. Yes. I'm using Mail. I was wondering if using other mail app wil cause the same problem because it's Lion 10.7.4 OR it is squarely Apple's Mail issue.

I'm tempted to switch to another mail app such as Postbox or Thunderbird. Any advise on this? Unless of course Apple satrt to resolve this problem soonest possible. I hope once Mountain Lion comes out this problem is resolve.

I'm also checking with my hosting company on this matter and expecting an answer form them anytime soon

I'm also having this problem. I just moved from SL to Lion 10.7.4 (my organization won't let me use ML yet) and for one gmail account attachments are appearing inline with the mime headers, PDF files appears as miles of base64 encoding. It's not happening on all email. I'll try the rebuild option when I have more time and bandwidth.

The problem certainly seems to be real but the situations under which it occurs is still not clear. The MIME headers for one instance were:

--_----------=_1320062253134950

Content-Disposition: inline

Content-Transfer-Encoding: 8bit

Content-Type: text/plain

.

.

.

--_----------=_1320062253134950

Content-Disposition: attachment; filename="FOO.pdf"

Content-Transfer-Encoding: base64

Content-Type: application/pdf; name="FOO.pdf"

JVBERi0xLjQKJeTjz9IKMSAwIG9iagpbL1BERi9JbWFnZUIvSW1hZ2VDL0lt

YWdlSS9UZXh0XQplbmRvYmoKMyAwIG9iago8PC9UeXBlL1hPYmplY3QKL1N1

YnR5cGUvRm9ybQovRm9ybVR5cGUgMQovTWF0cml4WzEgMCAwIDEgMCAwXQov

.

.

.

I think i have the same problem as everyone here:

1. Mac app corrupts email attachments (mostly PDFs for me so far).

2. Mac app fixes some, but not all when i do rebuild, or move to a different folder.

3. Mac app fixes some, but not all, when i download the attachment to my computer.

other than changing mail app for outlook, thunderbird, the only other solution i found was choosing on the preferences to NOT download the attachments for offline viewing. That one seems to fix the ones that i couldn't fix with the #2 and #3. Hopefully it fixes all.

Hope this helps a few people.

EDIT: I still had to do #3 even after choosing to NOT download the attachments. but its working so i don't mind.

I too have recently discovered many corrupted email attachments in my Apple Mail folders. I am using Imap accounts with Gmail. Appears to happen randomly with messages that contain pdf's that have been moved to folders. Attachments can be viewed and downloaded fine through Gmail when viewing in a browser. I downloaded and am testing Postbox. I have confirmed that the same attachments that are corrupted in Apple Mail are not corrupted when viewed in Postbox. Postbox is derived from, and formats its mail files in the same format as Thunderbird. So I would assume that Thunderbird would behave like Postbox.

Apparently this is a problem with Apple Mail and I would consider it a major software bug since I have been using Apple Mail as a local backup for my Gmail accounts and unknowingly my backups were randomly corrupted. Until Apple fixes this problem I am migrating to Postbox.

Simon, I have been having the same issue with mail using a macbook air and Imac. The only thing that worked is logging into my e-mail account directly through the web, and thereby sidestepping the mail software. I am continuously amazed by people like etresoft, who always give mac products the benefit of the doubt, even amidst strong evidence against it. It is as if they have suffered a massive mac indoctrination. Best wishes.

It's not 'complete and utter nonsense'. I have the same issue, but ....

I have an application on my Mac that monitors a networked camera. It takes pictures of movement and sends a JPG to myself and to the boss. Both of us are running same version of Lion.

I always receive the email with the JPG attached normally, the boss receives his as the unencoded MIME (if that the correct terminology) sometimes.

Therefore in our case;

- its not the sender

- its not Gmail ( we dont use gmail)

- its not the mail server, otherwise it would happen to both

- its not a global issue with the mail.app because it does not happen to both recipients, nor does it happen all the time.

It has to be the bosses own mail application, settings, imac. Therefore this thread is a great place to look for answers. Thankfully there are some by people who have actually solved the problem. Will try rebuilding the mail folders and see what happens.

Hmm, not sure if this is the same issue I was having but Postbox has been bulletproof since September and I have heard nothing from Apple that deals with Apple Mail's handling of the corrupt attachment issue in historical emails.

I have this issue also, only with PDF's.

Approx 2-3% are corrupted.