There is is apparently a need to be able to open Microsoft Outlook Message files (*.msg) in Microsoft Outlook on Mac OS systems.

There is an easy trick.

• Install brew if not already installed.
• Run brew install python (which now installs python 3.9).
• Checkout this repository.
• Run pip3 install -r requirements.txt --user.
• Using Automator create an application which can open an MSG File in Outlook (Run Shell Script), call it MsgViewer.
• Using Automator create an application which can run multiple instances of the bofore created Application (Run Apple Script), call it OutlookPreview.

#!/bin/bash
runpy3 () {
/usr/bin/env python3 <<'EOF' - "$@"
Place here the content of outlook_viewer.py
EOF
}
runpy3 "$@"

on run {input, parameters}
    set f to quoted form of (POSIX path of (input as text))
    do shell script "source ~/.bash_profile"
    do shell script "open -n -a MsgViewer.app --args " & f
end run

Copy both applications into the Applications folder. Associate the "msg" file extension with the OutlookPreview.