I have some software that I am using on my dedicated server to send email to new members.
When I enter the email settings, the same ones I use in Outlook, I get the below error when the software is trying to send an email. I am thinking this has to do with authentication? Anyone have any ideas on how to resolve this?
Failed to set sender:

localhost [SMTP: Invalid response code received from server (code: 501, response: : no local part)]
Thanks!
Dazed