I have a 3rd party application that requires SMTP to send invoices. My exchange environment is EXCH 2010. I went ahead and created a relay connector specifying correct IP addresses and
Authentication set to: TLS, Basic Authentication checked. Permission Groups: Anonymous Users, Exchange Servers checked. When I use my personal account it works, but when trying to use CUSTOMERSERVICE account gives me an Error: 535 5.7.3 Authentication Unsuccessful. I HAVE CHECKED THE PASSWORD FOR THE CUSTOMER SERVICE ACCOUNT AND AM ABLE TO LOG INTO OWA WITH IT.
This environment was transferred from legacy Exchange 03, I heave read that some permissions may have not migrated, please help.