Archiving email using Mac OS Mail app

stepons wrote:

I had assumed the full content of all messages would be locally synchronised with the remote server, so didn't consider network issues. There is a counter of messages left to copy which went to zero.

Those counters are not reliable. There are two parts to any email operation - updating the content and updating the index. Even if all the content is copied, if something goes wrong with the index, you’ll never find the content again.

I most often see this problem with flags. I flag important messages for later review when I have time. But sometimes, important messages mysteriously lose their tags and junk mail mysteriously acquires a tag. My guess is that this happens about 5% of the time. So that’s 95% perfect, right?

I'll have to take a look at the backups – I'm sure I have one from that time. I just don't feel that confident about the Mail app any more, but it seems like the only option would be to use a third party app, which might not be any better and doesn't have the same integration.

There are very few 3rd party e-mail apps available. Outlook is one. I know of another popular one that actually copies and stores your e-mail passwords on the internet. And, of course Gmail.

I would not recommend giving up on Apple Mail. Yes, it is ancient and decrepit. But generally it works really well. I’m not sure what happened with your e-mail archives. Plus, I don’t know anything about your computer itself. Maybe you have an old mechanical hard drive. That can complicate matters when you perform some big operation and then start using Mail normally. Those long-running operations can get queued up and might not finish. You just have to be careful with them.

And you also have to be a bit more forgiving. The world, especially the world of technology, just isn’t like it used to be. You have to be much more accepting of bugs, errors, flakiness, and data loss. The world is falling apart everywhere. Why should technology be any different.

stepons wrote:

I have several archive folders locally in the "On My Mac" section of the Mail app and have found two inbox archives with some messages that have a subject line but nothing in the body. (The sent mailbox archives for the same two accounts seem to be unaffected.) I have found at least two other questions here on discussions asking about the same issue, with several people clicking "I have this problem" on each. I myself lost the entire contents of some local archived mail folders a few years back, but realised too late so that my backups did not go back far enough. I think that time it was moving to a new MacBook that triggered the loss, but I switched using the restore from a backup process.

It is clear that locally stored folders "On My Mac" are not a safe place to archive email, so what is the best alternative? If I export the mailbox, how can I view the contents easily?

Thanks,

Why archive if it is an issue...?

I have "On my Mac" mail boxes going back to 2003 without issue—but I have never used "archive"

Archive emails in Mail on Mac - Apple Support

Mail User Guide for Mac - Apple Support

Change Mailbox Behaviors preferences in Mail on Mac

Import or export mailboxes in Mail on Mac - Apple Support

stepons wrote:

It is clear that locally stored folders "On My Mac" are not a safe place to archive email, so what is the best alternative? If I export the mailbox, how can I view the contents easily?

I agree with leroydouglas. I have never used Mail's built-in "archive" feature. I have no idea what it is supposed to be doing, but it isn't any kind of archive. I create my own mailboxes in the "On My Mac" section. I have one folder for "Received items" and another folder for "Sent items". Inside each is another folder for each year, going back to 1997.

I don't really trust Mail's ability to recover mailbox contents from backup. Perhaps that is the source of your problem. For example, when you tell Mail to "rebuild" a mailbox, it just deletes all of the contents and downloads it all again from the server. Ouch!

What I do when I'm going to migrate to another computer is use Mail's export functionality to export these archives to mbox format. Then I import them onto the new computer. Technically speaking, they are also backed up in Time Machine. I'm an advanced user so I could get them out of Time Machine if I had to. I don't know if Mail could automatically recovery them from Time Machine. I recommend this manual backup and restore process to make sure. It is a bit of a hassle, but I only have to do it every few years.

stepons wrote:

My question was not clear as I was not specific when I used the term archive.

It isn't your fault. It is Apple that uses the term "archive" to mean something that really isn't an archive.

I agree that recovering mail from a backup does not seem reliable and I will definitely export to an mbox and then reimport when changing machine in future. However, the most recent issue is from closing a mail account this circa June this year when I dragged messages from the IMAP account mailboxes to "On My Mac" mailboxes. It seems this process has 'lost' some messages' content except for the subject line. There is a significant number of messages affected. I have done nothing further – I installed Big Sur after the first update so that would have been at the end of last year.

It sounds like maybe there was a networking problem and those messages never got transferred completely. Another problem in Mail is that some operations can take a very long time to complete and the feedback and progress is very poor.

If you have a backup from that time, you should be able to locate the original messages. You won't be able to automatically import them, but you can manually open them in the Finder. They will open in Mail as stand-alone messages. You can then use the Move To operation to put them where they need to go. The biggest difficulty will be finding them in the backup. Mail's internal folders aren't designed for manual navigation.