: Use the Exchange Management Shell to set the download hostnames: powershell
: Send an email with an inline image to an OWA user. Right-click the image and select Copy Image link —it should point to your new download domain. Summary of DNS Record Values Record Type Host / Name TXT @ or blank MS=msXXXXXXXX Verify Domain Ownership CNAME owa mail.domain.com Alias for easier OWA access owa domain.txt
Set-OrganizationConfig -DownloadDomains @{Add="attachments.yourdomain.com"} Use code with caution. : Use the Exchange Management Shell to set