Unable to send as sender (Reason:550 5.7.1)

Unable to send as sender (Reason:550 5.7.1)


Hi,

We have several email addresses pointing to one department and when one of our reps tried to send an email using one of these addresses she received this message:

Error while processing the request! Unable to send message;Reason:550 5.7.1 Client does not have permissions to send as this sender

Can you please explain how to fix this?


Thanks