将macOS Mail.app存储移动到外部驱动器的最佳做法?

我的系统具有较小的内部存储(500GB),因此我已连接了相当快的外部存储设备(256GB),该设备将不断安装。为了释放内部存储空间,我想将一些数据移动到外部,可以将其格式化为“ MacOS Extended Journaeld” / HFS +或APFS。 Mac本身正在运行macOS 10.14“ Mojave”。

移动最简单的方法是Photos.app库,只需选择启动程序并在外部选择该库即可,但是该库太大(大约300GB),并且在不断增长,因此不是一个选择。将库分为两个是一种选择,但随后需要对两个库进行融合,而Photos.app并不能很好地支持使用两个库中的图像。

另一方面,电子邮件存储空间恰到好处!但是,我不确定到底哪个文件夹很重要,以及提供链接的最佳方法是什么,以便使一切正常工作并且不会经常损坏。

〜/ Library文件夹中的以下文件夹似乎与Mail.app相关:

~/Library/Mail
~/Library/Mail Downloads
~/Library/Containers/com.apple.mail

~/Library/Mail Downloads seems to be old with nothing inside it dated after 2013 - I gather that sometime in the 10.9 Mavericks era this was moved to inside ~/Library/Containers/com.apple.mail folder, so it can probably be ignored or even deleted after I look through it to make sure there is nothing of value inside.

这样就剩下了另外两个文件夹。如果我将它们复制到

/Volumes/external-drive/Mail-Storage/Library/Mail
/Volumes/external-drive/Mail-Storage/Library/Containers/com.apple.mail

and then make symbolic links at the expected places in the ~/Library folder will everything continue to work properly?

Would macOS aliases be preferred over Unix symbolic links? I think that if the name of the external-drive is ever changed, the symbolic links will break but macOS aliases would continue to work. The downside to an alias is that some lower-level Unix stuff does not know how to deal with the macOS alias. With that said, it looks like ~/Library/Containers/com.apple.mail is filled with all sorts of macOS alias files, so Mail.app does seem to be able to handle all of those.

This discussion Access to ~/Library/Containers/com.apple.mail/Data/ denied makes me think that Mojave's "entitlements" might make it challenging to move the entire ~/Library/Containers/com.apple.mail folder. Perhaps I should move the ~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads folder instead, since it seems to contain the majority of the data in the ~/Library/Containers/com.apple.mail folder.

所以我倾向于复制两个文件夹

~/Library/Mail
~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads

结束于

/Volumes/external-drive/Mail-Storage/Library/Mail
/Volumes/external-drive/Mail-Storage/Library/Containers/com.apple.mail/Data/Library/Mail Downloads

and replace the local folders in ~/Library with macOS aliases to the folders in /Volumes/external-drive/Mail-Storage/Library/.

要做的另一件事是确保别名位于

~/Library/Containers/com.apple.mail/Data/Library/Mail

通常指向文件夹

~/Library/Mail

正确解析到该文件夹

/Volumes/external-drive/Mail-Storage/Library/Mail

如果未更正它可能不会执行。

这是最好的方法吗?我错过了任何问题吗?

I guess I should encrypt the external-drive so the data is safe if someone walks off with the device using either the Finder to encrypt all the data currently on the device, or using Disk Utility.app to reformat the device with encryption - details on both are here among other places.

预先感谢您提供的任何见解。