We have setup the SMTP on our Azure Acceptance env with all the required information, however we fail to send an email from our Azure AD user using the O365 smtp. 

O365 configuration:

SMTP Host: smtp.office365.com
SMTP Port: 587
SSL Protocol: OFF
TLS Protocol: ON

Indicium configuration with SSL ON:

 "Email": {
            "TwoFactorEmailMessageService": "TSFSmtpMessageService",
            "SmtpServer": "smtp.office365.com",
            "SmtpPort": 587,
            "UseSSL": true,
            "SmtpEnableSsl": "Yes",
            "SmtpUsername": "notificationsuat@hartmannship.onmicrosoft.com",
            "SmtpPassword": "*******",
            "SmtpFrom": "notificationsuat@hartmannship.onmicrosoft.com",
              "SmtpFromDisplayName": "UAT Notifications",
            "DefaultPasswordResetTemplate": {
                  "FromEmail": "notificationsuat@hartmannship.onmicrosoft.com",
                  "FromDisplay": "UAT Reset Password",
                  "Title": "Password reset token",
                  "Body": "Your password reset token is <b>{resetToken}</b>."
                }
        }

Error 1 with above config: 2020-10-13T06:54:08.4273543+00:00 0HM3EN17KKVMK:00000001 ÂERR] System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM eAM0PR02CA0002.eurprd02.prod.outlook.com] 

Indicium configuration with SSL OFF:

 "Email": {
            "TwoFactorEmailMessageService": "TSFSmtpMessageService",
            "SmtpServer": "smtp.office365.com",
            "SmtpPort": 587,
            "UseSSL": false,
            "SmtpEnableSsl": "No",
            "SmtpUsername": "notificationsuat@hartmannship.onmicrosoft.com",
            "SmtpPassword": "*******",
            "SmtpFrom": "notificationsuat@hartmannship.onmicrosoft.com",
              "SmtpFromDisplayName": "UAT Notifications",
            "DefaultPasswordResetTemplate": {
                  "FromEmail": "notificationsuat@hartmannship.onmicrosoft.com",
                  "FromDisplay": "UAT Reset Password",
                  "Title": "Password reset token",
                  "Body": "Your password reset token is <b>{resetToken}</b>."
                }
        }

Error 2 with above config: 2020-10-13T06:58:33.3732869+00:00 0HM3F8L7PVBFM:00000005 ÂERR] System.Net.Mail.SmtpException: Error in processing. The server response was: 5.7.3 STARTTLS is required to send mail tAM6PR10CA0102.EURPRD10.PROD.OUTLOOK.COM]

 

Question: How do we configure the TLS if it is ON or OFF in the SMTP settings of Indicium? What are we missing ?