Confirmation mail doesn't render email links

[udoatgithub]

Hello.
Typo3 v. 7.6.32 / direct_mail 5.2.0 / registeraddress 2.0.1

The registration form works fine. The Name, surname and email-adress is written to the db and flagged as hidden. The confirmation mail doesn`t render a link to confirm and unhide the entry. Just the static values from the language files were transmitted:

After having a look at the source of the email file, there is a link visible.
If i copy the link and paste it to a browser, there will nothing happen to the db...

Anyone any idea? Thanks, Udo