AWS WorkMail inbound rules

This indicate that there's an inbound mail routing issue. use the following steps below to identify and fix the issue:

1. Check the MX record for the domain associated with your Amazon WorkMail organization. WorkMail should be the only entry and should have the lowest priority. Multiple MX records can lead to the wrong service receiving messages. For more information about MX records, see Verifying domains.
2. Check the Domain-based Message Authentication, Reporting, and Conformance (DMARC) settings for your organization in the Amazon WorkMail console. DMARC records are used to protect against common attacks, such as spoofing or phishing, that can compromise a user's account credentials. For more information about DMARC, see Enforcing DMARC policies on incoming email.
3. Check the Amazon Simple Email Service inbound rule. If the rule contains actions other than Amazon WorkMail, those actions can fail and cause Amazon WorkMail to stop receiving mail. For more information about Amazon SES rules, see Integrate with Amazon WorkMail action in the Amazon Simple Email Service Developer Guide.
4. Enable message tracking in Amazon WorkMail, and then check the logs for delivery problems. For more information about message tracking, see Enabling event logging.