Could you tell me how to set external mail with smtp auth?

I tried to send external mail after setup rul1 in jde.ini with enterprise server and mail preferencein address book . But I received an error messege as "Response from the SMTP server is <553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)"
How can I set anymore? Please tell me about solution!

EO 8.10, EO Tools 8.94
SQL-Server in HP
MS-2000

Sounds like it could be an issue with the mail server. Not allowing relaying or any mail from that domain.