Here are the values I suggest you try:
Domain Name= the undotted name of your Windows domain if you are in a domain; otherwise the undotted name of your computer, e.g. mydomain or mycomputer NOT mydomain.com or mycomputer.com.
If
[email protected] is a valid email address that can send mail out from your site using the password 1234, then,
User Account Name = testuser
and
User Account Password = 1234
and
SMTP Server Name(s) = example.com
Here is the
manual.