Forum Discussion
Mail relay to Office 365 from IIS SMTP Relay
Since about a month we cannot relay email from our IIS SMTP Relay to Office 365. This has worked for a long time, therefore I do not get why it is not working anymore. The account used is still activ...
Verify you are not using "Integrated Windows Authentication" and you are using "Basic Authentication" for Outbound Security. Also the "Domain Name" should not match your Email Domain since you want to email to send via the Smart Host.