I have an email address with a dot in it, and when I try to put:
cc:firstname.lastname@example.org it says that the email can not be sent, I figure the . is causing some problems with the code. I am putting this in the "ADDITONAL HEADERS" box, it works fine if i put the email address as the main sender address.
Are you able to replicate this problem or is it something on my end? I am using a wp-mail to send mail through our mail server rather then using wordpresses built in features.