Mail app files in Library/Mail take a lot of space

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Mail app files in Library/Mail take a lot of space

While taking a disk cleaning, I noticed that my Mail app data takes over 60GB of disk space. I've been archiving my emails into .rtf format regularly and deleting not needed messages with large attachments, so this was a mystery to me. I started to dig up the Library/Mail folder. It contains three subfolders: V2, V5 and V10. V2 takes less than MB and V5 takes 15GB and V10 rest. I started to look into V10 and realised that it is my current emails there. So I started archiving them from Mail App into .rtf and noticed that it's roughly 10x the size the messages in .rtf format that they take in email-format. OK, I can live with that, I'm sure there's plenty of data and search indexing etc there. I ended up with 20+ GB for V10 folder.

This is where the plot thickens. I took a look into V5 folder, and realised that it's basically an old backup of some previous year email archive. How do I know this? It contains mailbox-files that I have backed up and deleted years ago (I name each mailbox after a client and store all client communication emails there, so I know which ones I've backed up and deleted)! Has there been some kind of error in the Mail app file handling, and it has for some reason duplicated my email data?

My question is: What to do with them? I don't want to waste 15GB of disk space into years old messages that should have been deleted already. I cannot access those mailboxes anymore in Mail app UI, because I deleted them back in the years, can I just delete them manually? If I remove them, will my Mail app go crazy or something?

Posted on Jan 29, 2024 6:20 AM

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Answer 1

etresoft

Level 9

56,124 points

Jan 29, 2024 8:38 AM in response to Mikko Sillanpää

Mikko Sillanpää wrote:

While taking a disk cleaning

That's a really scary thought.

I've been archiving my emails into .rtf format regularly and deleting not needed messages with large attachments, so this was a mystery to me.

In the future, I recommend using Apple Mail's "Export mailbox" functionality. This will export a mailbox into an "mbox" file containing all of your e-mails in their original formats. This is the highest-quality, most portable type of e-mail archive you can do.

Has there been some kind of error in the Mail app file handling, and it has for some reason duplicated my email data?

A bug in the software! No! 😄

My question is: What to do with them? I don't want to waste 15GB of disk space into years old messages that should have been deleted already. I cannot access those mailboxes anymore in Mail app UI, because I deleted them back in the years, can I just delete them manually? If I remove them, will my Mail app go crazy or something?

It is a bit tricky. Digging into hidden "Library" folders and similar is extremely dangerous. That's a good way to lose data and corrupt your data permanently.

You were correct that this is an old e-mail database. I think we are on V10 or V11 now, depending on how addicted one is to updates. (I'm happy at V9.) It is entirely possible that some old version of Mail crashed or had some other bug that cause it to neglect to delete the old data and you just copied it along. You should be able to safely delete it.

But you should always have an up-to-date backup. The more of this kind of "cleaning" you do, the more likely you are to need a backup and restore.

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Mail app files in Library/Mail take a lot of space

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