Why can't CPGuest send e-mails to recipients that contain dot "." in the email address?

[raff]

How can I fix this?  I am trying to send an e-mail to a recipeint whose address contains the following format: "firstname.lastname@somedomain.com".   

The send e-mail form complains with this error message every time:   "Please provide the recipient’s email address."

But when I change the recipient to: "myaccount@somedomain.com"  It's not an issue.  I am sure I am not first to run into this issue. Any thoughts? 

[raff]

Apologies for the confusion.  This is not really a CPGuest issue ;)  Was my own issue.