[Typo3] Dmailer need text mail

[Marcel Trichét]

Hello,


what I have:

dmailer installed and working ok for HTML mails.
A site with events from tt calendar plugin.

What I want to achieve:

i need the mails to be send in plain text. But when I send them in plain 
text format it always sais [Unrendered content] where my plugin reads 
the events.

How can I achieve that all records from tt_calendar are rendered also 
when sending newsletters in plain text format?

thanks