Thank you for your post, and I apologize for the late reply.
Assuming you are using Send Mail with E-mail client, have you tried using Send Mail via SMTP server? If so, does this work?
For clarification, are you just sending the email address, or are you also trying to send the name with the email address?
I also noticed Knowledge Base Article #7083 may be relevant.
Any other information you can provide may be helpful.
I know some time has passed since you initially posted, so if you have found a resolution, please post so others who run into the same issue can benefit.