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macrumors member
Original poster
Jul 22, 2002
Los Angeles, California

I'm wondering if it's possible to make a backup of the current version of (Ventura) so when I update to Sonoma I can then replace Sonoma's with the Ventura version? (I rely on the MsgFiler plugin for filing messages into folders and Apple is removing plugin functionality from Sonoma's

Is this possible? Do I need to do anything more than copy the app or will I need to duplicate and restore files/folders from other parts of my Mac to make this work?

So in a nutshell – I want to update to Sonoma when it comes out...but somehow use Ventura's

Thanks for any advice.



macrumors 68000
Sep 18, 2013
Doubt you can, because of SIP. However, disabling SIP might help. I'll let more experienced users here pipe in, but it's possible depends on certain system frameworks.
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macrumors 6502a
Jun 28, 2002
It's probably not a good sign that I don't know what SIP is or how to go about disabling it.
It is at the very least a sign that you will probably want to spend some time understanding what SIP (System Integrity Protection) does, and why you probably don't really want to disable it.
You can learn more here:

It's also a sign that you're probably going to want to find another solution for your email long term (preferably sooner rather than later), as relying on deprecated (in this case removed) software functionality is just going to cause you more issues going forward.

That said, in the meantime a relatively simple and safe solution would be to virtualize macOS Ventura on Sonoma and access the Ventura mail app (with the plugins you need) via that. There are lots of free applications that utilize Apple's lightweight virtualization framework that should be able to accomplish this task quite easily.
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macrumors 6502a
Sep 1, 2021
Knowing that features/plugins you use may no longer work on the newer version, why upgrade?

I can upgrade officially to Monterey [MacBook Pro 2015] but decided to go back to Catalina... Monterey has some features only available for Apple Silicon devices and Catalina is the last intel only release that is why I decided to not go beyond Catalina even though I am using iOS 16.7 on iPhone 11 Pro Max...


macrumors Penryn
Feb 20, 2009
I'm thinking that with Sonoma, with Mail being one of Apple's primary applications, it's located within the "sealed system volume" and there is NO WAY that you will be able to use the older version after doing an upgrade. You (as the end user) can't even "see" the sealed system volume.

OP wrote:
"It's probably not a good sign that I don't know what SIP is or how to go about disabling it."

Then you had best not be fooling with anything that's "in there".
It could lead to some nasty problems.

If you upgrade to Sonoma, you're going to have to get used to the "new"
That's pretty much all there is to it...


macrumors 601
Mar 10, 2009
While you can simply copy-paste the Mail app from Ventura into Sonoma /Applications, it doesn’t work. I tried.

"Termination Reason: Namespace DYLD, Code 4 Symbol missing
Symbol not found: _$s6MailUI0A11FeatureFlagO25zeroKeywordSearchMockDatayA2CmFWC
Referenced from: <A082FB4B-8662-3FF1-AB3D-9A2B9B0384AE> /Applications/
Expected in: <B668ABCE-793C-3863-802F-4918C2AE459D> /System/Library/PrivateFrameworks/MailUI.framework/Versions/A/MailUI"


macrumors regular
Jan 14, 2014
Near Brisbane, Australia
Wow! It disturbs me that I have been using mail for years (since Mountain Lion at least) and I did not know that the MsgFiler plugin existed. :(:mad::(

This is the feature that I have used 3rd party mail clients for and putting up with their bugs, etc. Very sad.
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