Yahoo recently made a security change that has resulted in bounce backs of marketing emails that are being sent through NCR Silver.
Bounce backs are occurring when the Sender's From address (your default email settings under Settings > Company Information />Email Marketing Information) is a Yahoo email account.
Yahoo’s new security settings require that all emails sent from a Yahoo account must match the domain of the server sending the email.
These bounced emails can result in recipients being removed from your email lists due to the addresses’ bouncing.
Moving forward, we recommend that you send all email marketing and emailed receipts with a non-Yahoo email address from NCR Silver. To update this information log in to the Back Office, select Settings > Company Information and scroll down to the Email Marketing section and update the email address in the From Email field.