desktop-file-validate shows multiple errors and warnings about data/usr/share/applications/ayatana-webmail.desktop

[N0rbert]

Steps to reproduce:

1. Have Debian 12 installed

2. Install build-depends, clone the repository

   sudo apt-get build-dep ayatana-webmail
   sudo apt-get install git
   cd ~/Downloads
   git clone https://github.com/AyatanaIndicators/ayatana-webmail
   cd ayatana-webmail
   python3 setup.py build
   

3. Run desktop-file-validate

   desktop-file-validate data/usr/share/applications/ayatana-webmail.desktop
   

Expected result: desktop file is correct.

Actual results: desktop file has multiple errors and warnings as shown below:

$ desktop-file-validate data/usr/share/applications/*.desktop
data/usr/share/applications/ayatana-webmail.desktop: warning: key "NotShowIn" in group "Desktop Action Clear" is deprecated
data/usr/share/applications/ayatana-webmail.desktop: error: value "Messaging Menu;" for key "NotShowIn" in group "Desktop Action Clear" contains an unregistered value "Messaging Menu"; values extending the format should start with "X-"
data/usr/share/applications/ayatana-webmail.desktop: warning: key "NotShowIn" in group "Desktop Action Compose" is deprecated
data/usr/share/applications/ayatana-webmail.desktop: error: value "Messaging Menu;" for key "NotShowIn" in group "Desktop Action Compose" contains an unregistered value "Messaging Menu"; values extending the format should start with "X-"
data/usr/share/applications/ayatana-webmail.desktop: warning: key "NotShowIn" in group "Desktop Action Sent" is deprecated
data/usr/share/applications/ayatana-webmail.desktop: error: value "Messaging Menu;" for key "NotShowIn" in group "Desktop Action Sent" contains an unregistered value "Messaging Menu"; values extending the format should start with "X-"
data/usr/share/applications/ayatana-webmail.desktop: warning: key "NotShowIn" in group "Desktop Action Inbox" is deprecated
data/usr/share/applications/ayatana-webmail.desktop: error: value "Messaging Menu;" for key "NotShowIn" in group "Desktop Action Inbox" contains an unregistered value "Messaging Menu"; values extending the format should start with "X-"

Please fix the desktop file.