Error - SmtpFailedRecipientException: Mailbox unavailable

Epicor ERP 10
,
1

Hi all
When trying to send an SSRS report by email, I got this error :

Program Ice.Services.Lib.RunTask raised an unexpected exception with the following message: RunTask:
System.Net.Mail.SmtpFailedRecipientException: Mailbox unavailable. The server response was: 5.7.54 SMTP; Unable to relay recipient in non-accepted domain

The problem is with external addresses only (eg. @gmail.com). What is weird is that is only an issue on production server. If I try the same thing on a test environment (3 different), is it working. We use the same smtp server on all environment.

The SSRS server is the same for all non-production server.

I’ve check all configuration that I am aware of and they are the same.
Any idea of what is causing this issue?

Thanks for your help

2

What are you using for a SMTP server?

3

Not sure about it, but it is working for external addresses on other application we have.