If I set the "From" field to
[your-name] <[your-email]> as in the example form given after installation, all messages fail to send.
If I change that to just the
[your-email], it works fine.
I'm running WordPress 2.7 on Windows Server 2003, using IIS's SMTP server.
I've worked around the problem for now by just using the email address in the from field, but it would be nice to be able to use the name in there too :)