If a keyboard shortcut is defined for an "Input Action" (Trinity Control Center
-> Regional & Accessibility -> Input Actions) and the triggering key is
XF86Mail, then pressing the XF86Mail button opens the email client regardless of
what action is assigned to it.
If the action is deleted or assigned to a different shortcut, the mail program
does not open when pressing XF86Mail.
This started happening a few days ago after an apt-get upgrade on Debian.
# dpkg -s tde-trinity
Version: 4:14.1.3-0debian12.0.0+0
-- Davide