Users occasionally ask how to avoid the default authentication that occurs when sending emails. This is usually because the target SMTP server does not support NTLM and will reject requests that attempt to authenticate this way. This feature was implemented in Notifications since the 2016 R2, but because of scheduling constraints, a user interface was never implemented. To configure the service to connect anonymously create a string type attribute in the Configuration Database at \OSIsoft\PIANO\DeliveryChannel\194caabd-7307-4e86-b25e-4ddbdc370d2c|SMTPServerUseDefaultCredentials and set the value to False. A similar option can be configured for the backup server, with an attribute named BackupSMTPServerUseDefaultCredentials. The value will be picked up automatically the next time an email is sent.
In Notifications 2017 R2, we plan to allow anonymous connections as an option that you can configure (along with with basic authentication using a username/password) in PI System Explorer.