for anyone interested, i just found the template’s directory
/opt/zammad/app/views/mailer/email_oversized
i created a new template based on my locale even though it works, i need to recreate it every time at containers restart because the entrypoint.sh delete all files during the initialization (i tried to volume mount the file with read only permission but the init would fail to start at all zammad)
i’ll wait for a webui editor integration of those templates