The server response was: 550 5.1.1 User unknown

brindha

I m using CU 400(SMTP Mail) to send email to customer with pdf attachment. It is working good. But when I send more than one recipients(example 10) and one of them unknown email address.

I received error message from SMTP Server "(0x8004020F): The server rejected one or more recipient addresses. The server response was: 550 5.1.1 User unknown"

For this scenario, I have the following issue;
1. 9 recipients are not receiving emails because of 1 email address is unknown.
2. SMTP server has not returned the unknown email address.

Is there any solution? Please advise.

Thank you.

vremeni4

Hi,

Did you try to send 10 individual emails rather then one email to 10 people?

Thanks.

brindha

Hi, I got solution for these issues.

Actually, I have to add my(user) IP address into Exchange Server(Open Relay Server). Now it works like normal email. That means sender received Undeliverable notification and also email received by rest of 9 recipients.

Thank you for your response.