Email shows HTML tags

Hi,  although I've set msg_buffer_size:10000  in sm.ini  there are some records where the {$RECORD.description} Text Box is larger than 10000 characters, so the mail shows the HTML tags

¿Is there any function, like substr i wonder, or any other way to format the {$RECORD.description} field in the HTML Editor to limit/truncate it?

Thanks in advance.