Have a new SBS 2011 network. Everything seems to be working fine. Exchange email flow is working, OWA is working. The SBS 2011 installation was a fresh install, not a migration. They had an SBS 2003 server.
There is a voicemail box in the network that is supposed to automatically send voicemail attachment emails to the exchange users when someone calls and leaves a voicemail message. It was working when they had SBS 2003. Now it is not working.
They are using SMTP port 25. The errors they get are:
504 5.7.4 Unrecognized authentication type.
550 5.7.1 Client does not have permission to send as this sender
Can anyone tell me what authentication or permission changes have to be made and how to make them?