Field in related module will not render in email-template

[dafnie]

Hi

We have inserted this snippet {Materiel.maskinnr} in an email-template. "Materiel" is a custom base module and maskinnr is a intriger-field.
The email-template is used on the qoute-module. "Materiel" is added in a link field in the qoute-module.

The email subject "Card - {qoute.sn}, masknr: {Materiel.maskinnr}" -> renders as "Card - 23456, masknr: {Materiel.maskinnr}"

Why is a materiel.maskinnr not rendered?

I have tried {{Materiel.maskinnr}} and {{{Materiel.maskinnr}}}, but still no result.