Workmail Exchange server outages/delays

It sounds like you're experiencing mail routing issues with your Amazon WorkMail account, specifically with outbound mail when using Microsoft Outlook for Android via the Exchange protocol.

For outbound mail issues in WorkMail, there are several potential causes to investigate:

1. SPF record configuration: Ensure your SPF (Sender Policy Framework) record includes Amazon SES. You can verify this on the domains page in the Amazon WorkMail console. Incorrect SPF records can cause delivery problems.

2. Permissions issues: WorkMail may need proper permissions to use your domain for sending emails. This can sometimes occur even after years of successful operation if there have been changes to policies or configurations. You might need to re-add your domain in the WorkMail console to reset permissions.

3. SES permissions: There could be an issue with the permissions between WorkMail and Amazon SES (Simple Email Service). WorkMail uses SES for email sending, and if these permissions are not properly configured, you might see delays or failures in email delivery.

4. Delivery delays: The symptoms you're describing (delays of hours or failed delivery reports) could indicate transient communication failures between Amazon SES and recipient mail servers.

Since you mentioned that sending via IMAP with your Yahoo account works fine while WorkMail Exchange sending is delayed, this suggests the issue is specific to your WorkMail configuration rather than your device or network.

To troubleshoot further:

• Enable message tracking in Amazon WorkMail to check logs for delivery problems
• Verify your domain settings in the WorkMail console (all DNS records should show green checks)
• Check if there are any custom policies in Amazon SES that might be affecting email delivery
• Consider temporarily switching to IMAP/SMTP for your WorkMail account in Outlook for Android to see if the issue persists

If these steps don't resolve the issue, you may need to contact AWS Support for further investigation, as there could be region-specific issues affecting the eu-west-1 region that aren't appearing in your AWS Event logs.
Sources
Mail routing - Amazon WorkMail
One Organization in Workmail not able to send or receive | AWS re:Post
I can receive emails BUT can't send | AWS re:Post
Monitor email delivery delays | AWS re:Post