Make Workflow Manager not retry if NDR is permanent. Code starts with 5. Valid users get multiple email notifications due to invalid users
100s of SP Designer WFs are being used in SP Online sites. Emails are sent to SP groups and AD security groups which sometimes contain disabled/invalid users who are no longer in Azure AD. Due to this Exchange Online returns NDR. Workflows retry due to NDR even for the valid users. This causes many duplicate emails to the end users.
When users receive repetitive emails for the same WF notification/action it gets confusing for them to decide what action they need to take. It affects their productivity and causes a lot of inconvenience for them.
Current workaround is to disable Directory based edge blocking. It poses security risk, and is not a long term solution.
There are 2 types of NDR permanent and non-permanent. Permanent condition such as invalid email address start with 5. Please have Workflow Manager not retry if NDR is permanent. Code starts with 5. If the condition is permanent, there is no reason to keep retrying.