Thanks. I’ve defined [first_name] and [last_name] manually in the eMails and it works.
Thanks for your answer. This increased the size of the comment fields indeed, but it didn’t increase the size of the textfield in the contact form i’m using (Contact form 7).
So I simply used
textarea { height: 8em; }
instead (without the #comment) and now everything seems to be fine.
Could you tell me whether there are any negative side effects doing it like this?
Thanks!