IssueAfter upgrading from Tableau Server version 9 to Tableau Server 10 and higher, some subscriptions might fail to send with messages and the following error might occur in the admin view:
550 5.7.1 Client does not have permissions to send as this sender
Additionally, the following error might be found in the backgrounder logs:
"ERROR : com.tableausoftware.model.workgroup.util.EmailHelper - SMTP server login credentials failed. Cannot send email."