Mac Mail won't fully export

[sean000]

I am helping a friend migrate email from an old Macbook (I think it's running 10.6.8 or something not much newer) to a new Macbook. She already used Time Machine to transfer her personal files and settings, but she asked me to take a look because her email did not fully transport.

On her old mac she used Mac Mail to connect to her email service using POP. Then she would move messages to mail folders stored on her Macbook. We have her set to access the same mail service using IMAP on her new device. That's working fine, but we are not able to get a complete export of the mail stored on her old macbook. For example she has a local folder on her old Macbook that has more than 12,000 messages, but we can only get about 2,000 or so to export. We have tried multiple times an it exports the same number each time.

There is no progress indicator as Mac Mail performs the export, and there is no error. We let it churn away for hours, but it still only exports the same fraction each time.

Any suggestions? Could the massive number of messages she has stored in that one folder be a problem? I'm not aware of any folder or export limitations. I suppose there could be some corruption there. Rebuild and repair appears to be for IMAP folders, but these are local folders. I suppose I could also try going to the maildata folder and renaming/moving the envelop.index files to for the app to rebuild the indexes for the local mailboxes. Then maybe export will work? I'm a bit skeptical about that solution because I don't think the export transfers the index anyway. This isn't a problem with search, but perhaps a corrupt index is causing the app to display the wrong message count?

Also thinking about having her create four new folders and moving the messages from the giant 12,000 message folder into the other smaller folders. Maybe that will work? I think it's only this giant folder that isn't exporting properly. She says she is missing mail from others, but I think I helped her figure out that wasn't really the case (just sorted differently)

Sean

 

[BrianBaughn]

You're probably on the right track and I'd guess that you've got at least one corrupt message in that 12,000 message folder. You might even run into snags trying to split the messages into smaller quantity folders. The corrupt message may interrupt the moving/copying process.

I don't know of any better way than copying in small quantities because you have to keep track of what's been copied and what failed.

One method would be to create the new, smaller folders and then performing a search in the big folder that will yield a reasonable amount of results. Copy the results to one of the new folders and, once the copying is complete, compare the number of emails in the search results to the number in the new folder. If they match, you should be able to delete the search results from the original. If they don't, you may have found a corrupt email amongst them. Rinse and repeat.

 

[sean000]

Thanks Brian,

I have asked the owner of the mac to try splitting the problem folder into smaller ones. Good idea to identify messages that it would make sense to group together into one of the new folders.

Sean