Concept: Amazon SES Email Suppression List

When Workday sends an email to a recipient that results in a permanent failure to deliver (permanent bounce), Amazon Simple Email Service (SES) adds the recipient’s email address to an email suppression list. Workday will not attempt to send emails to email addresses while they are on the suppression list. The most common cause for a permanent bounce is when a receiving mail server indicates that an email address doesn’t exist in your system. Other common causes of permanent bounces are internal routing and system configuration issues.

The suppression list has an automated removal feature for permanent bounces that distinguishes between temporary delivery issues and permanent delivery failures. When an email address experiences a:

Temporary delivery issue and is removed from the suppression list, subsequent emails sent to that address may be delivered successfully.
Permanent delivery failure and is removed from the suppression list, subsequent emails sent to that address will not be delivered, and the email address will be added back to the suppression list.

This approach gives temporary delivery issues time to resolve themselves. It also protects the shared myworkday.com domain’s email reputation and deliverability rate for all customers by preventing email delivery failures.

Workday uses an incremental approach when removing emails from the suppression list. The amount of time an email address remains on the suppression list increases based on the number of times it has resulted in a permanent bounce. The time increases by a multiple of 2 for each additional suppression and is capped at 48 hours. For example: