Problem with international chararcters in senders email

Hello,

We have a customers who sends batches of email to internation people with CFMAIL. So there are international characters involved in the emailadresses, like:

willem.solböck@company.com
frédéric.salterr@company.com
jean-françois.boquet@company.com

These emails are ending up in the undelivrable folder of Coldfusion. It this because those charcaters are invalid or is it a setting in Coldfusion to send emails with this kind of internation characters.

Thank you in advance.