How can I resolve issues with email delivery delays to certain recipients in Exchange?

1. Check the domain settings of the recipients in question.
2. Set up delay notifications for each recipient.
3. Verify that each email is accepted by the recipient’s server.
4. Check the server logs on the sender’s Exchange server.
5. Check routing issues to specific domains.
6. Verify Exchange settings for message size limits.
7. Revise the DNS Mail Echange records for each domain.