I have a few domains on my server, but only the primary can receive emails. Whenever I send an email to another domain on my server, I get the following error:
Reason: Remote SMTP Server Returned: 503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.
I'm using Windows Server with MailEnable, I need all account to be able to send / receive emails with no issues, but without allowing unauthenticated users to send emails.
Unfortunately I am unable to provide remote access to the server, you will need to tell me what to do.