Hi Thom A

Even if I leave out the name, and only try to send to an email address like jørgen@ærø.dk, I get the same error.
Lets say that the domain part of the email address is represented by only normal ascii characters (below ascii 127, like @varmt.dk), but the local part consists of a single special character (like jørgen@), then the error occurs.
The local part may according to the standard consist of almost any character. Even with quotes around the local part, as recommended, the result is the same error.