Plugin Not Visible in “Manage Plug-ins”

This article DOES NOT apply to MailSuite running on Big Sur.
If the plugin is not visible on Big Sur, please create a support request.

Issue

MailSuite app and components are installed, but the SmallCubed MailSuite plugin is not visible in Mail’s “Manage Plug-ins”.

There are three possible reasons for this, each with a different set of procedures to resolve the problem.

1. Sandboxing Issue

For Sandboxing purposes, Mail makes a symlink folder ~/Library/Containers/com.apple.mail/Data/Library/Mail that points back to the user folder ~/Library/Mail. Mail reads information from the ~/Library/Containers/com.apple.mail/Data/Library/Mail sandbox folder and not the user folder.

Sometimes when updating a computer to the new OS, manually or through Migration Assistant, the ~/Library/Containers/com.apple.mail/Data/Library/Mail is created as an actual folder rather than a symlink. When this happens, when the user folder is updated, the ~/Library/Containers/com.apple.mail/Data/Library/Mail is not, so Mail doesn’t see required files.



This can be checked using the terminal commands below:

ls -lad ~/Library/Containers/com.apple.mail/Data/Library/Mail

This should return

/Users/Username/Library/Containers/com.apple.mail/Data/Library/Mail -> ../../../../Mail

A visual check can also be done by looking at the ~/Library/Containers/com.apple.mail/Data/Library/Mail **. If it has a small arrow in the left corner, it is a “symlink”.

Show Mail Folder Symlink

** If you are not familiar with the hidden user library(~/Library/), use the Finder’s menu: Go -> Go To Folder… and paste in ~/Library.

If the terminal command does not return the required path or the folder does not display as a symlink, we have a utility to resolve the issue.

Instructions to resolve the Sandboxing Issue

1. Quit Mail
2. Double-click SANDBOX UTILITY APP to download the utility.
3. In the Downloads folder double-click the Repair Mail Sandbox.zip file
4. Give the Repair Mail Sandbox.app “Full Disk Access” in your "Security & Privacy" System Preferences
   Give Repair Mail Sandbox.app Full Disk Access
   

5. Double-click Repair Mail Sandbox.app. The script will tell you what it is doing and let you know if it was needed.
6. Open Mail and check to see if SmallCubed MailSuite shows up in the “Manage Plug-ins” window
7. Delete the Repair Mail Sandbox.app, and remove it from your "Security & Privacy" "FullDisk Access" list

The other two causes of this issue are related to Apple Mail’s DataVaults folder, which was introduced with “System Integrity Protection” (SIP) in Mojave. The DataVaults folder is created by Mail the first time it starts up. When SIP is enabled, this is a hidden folder. When plugins are installed, Mail puts a copy of the plugin into the DataVaults folder. If the plugin version in the DataVaults folder doesn’t match the one in the ~/Library/Mail/Bundles folder, Mail won’t load the plugin, and it is not visible in “Manage Plug-ins”.

The DataVaults folder has to be created by the Mail app.

2. No access to DataVaults Folder

Sometimes when restoring users data from a backup or with Migration Assistant, the DataVaults folder is also restored. However, because it is a copied folder rather than one created directly by Mail, it is not accessible to the Mail app. When this happens, the DataVaults folder needs to be deleted so it can be recreated the next time the Mail is opened.

Instructions for Deleting Mail’s DataVaults folder

Disable SIP

1. Restart your Mac and hold down the ⌘+R keys so that your Mac will reboot in Recovery Mode
2. From the “Utilities” menu, choose Terminal.
3. In the Terminal Window, type: csrutil disable; reboot and press Return.

Remove the DataVaults

1. After your Mac restarts, use the Finder’s “Go” menu and “Go To Folder…” ~/Library/Containers/com.apple.mail/Data/
2. Select the folder “DataVaults”.
3. From the Finder’s “File” menu, hold down the Option (⌥) key and select “Delete Immediately…”. (or hit ⌘⌥⌫) – note: do not move or drag it to Trash as this will leave it stuck in the Trash once SIP is re-enabled.

Re-Enable SIP

1. Restart your Mac and hold down the ⌘+R keys so that your Mac will reboot in Recovery Mode.
2. From the “Utilities” menu, choose Terminal.
3. In the Terminal Window, type: csrutil enable; reboot and press Return.

3. Cannot Find DataVaults Folder

In Catalina, if the user’s home folder is on a separate partition/drive and not in the standard location /Users/username folder, Mail doesn’t find the hidden DataVaults folder. As a result, the SmallCubed MailSuite.mailbunble file needs to be added to the ~/Library/Containers/com.apple.mail/Data/DataVaults/MailBundles/Library/Mail/Bundles folder manually.

Instructions for Adding SmallCubed MailSuite.mailbundles to Mail’s DataVaults folder

Disable SIP

1. Restart your Mac and hold down the ⌘+R keys so that your Mac will reboot in Recovery Mode
2. From the “Utilities” menu, choose Terminal.
3. In the Terminal Window, type: csrutil disable; reboot and press Return.

Copy SmallCubed MailSuite.mailbundle to the Data Vault/

1. After your Mac restarts, use the Finder’s “Go” menu and “Go To Folder…”: ~/Library/Mail/Bundles
2. Copy the ~/Library/Mail/Bundles/SmallCubed MailSuite.mailbundle file into the ~/Library/Containers/com.apple.mail/Data/DataVaults/MailBundles/Library/Mail/Bundles folder.

Re-Enable SIP

1. Restart your Mac and hold down the ⌘+R keys so that your Mac will reboot in Recovery Mode.
2. From the “Utilities” menu, choose Terminal.
3. In the Terminal Window, type: csrutil enable; reboot and press Return.

Note: If your user folder is on a separate partition, you will have to go through this procedure each time the SmallCubed MailSuite.mailbundle file is updated. Luckily most updates that are released only update the components of MailSuite and not the mailbundle file.

Major OS updates will require an update to the mailbundle file, but maybe when macOS 10.16 is released, this Apple pathway bug will be resolved.

Contact Information

If you have further questions, or MailSuite doesn't act as you expect, you can contact us at the following email address: support@smallcubed.com.