SES not sending mail to a perticular user

If you're experiencing issues with Amazon SES not sending emails to a particular user, especially for iCloud mail, there are several steps you can take to troubleshoot and resolve the problem:

1. Verify the recipient's email address: Ensure that you have the correct email address for the iCloud user. Even small typos can cause delivery failures.

2. Check your SES sending status: Log into the Amazon SES Console and review your account dashboard to ensure your sending privileges haven't been suspended.

3. Look for bounces or rejections: Check if you're receiving any bounce notifications or rejection messages for this specific iCloud address.

4. Contact the recipient: Ask the iCloud user to check their spam or junk folder, as the email might have been filtered incorrectly.

5. Consider greylisting: Some ISPs, including iCloud, may use greylisting to combat spam. This can cause temporary rejections of emails from unknown senders. SES will automatically retry sending these messages, so the email might be delivered after a delay.

6. Review your sender reputation: Ensure you're following best practices to maintain a positive sender reputation, which can affect deliverability to specific domains.

7. Check for domain-specific issues: There might be temporary issues with delivering to iCloud addresses. You can try sending to other email providers to see if the problem is specific to iCloud.

If these steps don't resolve the issue and you have a paid AWS Support plan, consider opening a support case with AWS. Provide them with the specific iCloud address you're having trouble with, along with any relevant message IDs or request IDs from your SES sending attempts. They may be able to provide more detailed insights into any delivery problems specific to iCloud addresses.
Sources
Amazon SES Delivery problems - Amazon Simple Email Service
Amazon SES Delivery problems - Amazon Simple Email Service