PHP Mail Invalid Address Server Response
From Birnam Designs Wiki
Sometimes when sending email via PHP mail() function a warning returns:
SMTP server response: 501 5.5.4 Invalid Address
This tends to happen when the address is formatted like this:
Recipient Name <recipient@email.com>
Theory: the server interprets the < and > symbols literally and replaces them with > and <, which is read incorrectly.
The solution is limiting, but you need to format emails on with address:
recipient@email.com
