Finding Unused Proxy Addresses for Exchange Online Mail-Enabled Objects

Hi,

The PowerShell + message trace approach is a solid method. Once you identify proxy addresses that haven’t appeared in historical message traces, here are the recommended next steps:

What to do with unused proxy addresses?
Validate Before Removing

Before making any changes, verify:

• The proxy address isn’t used for any forwarding, shared mailboxes, applications, or SMTP relays
• The proxy is not part of any old email domain still active for routing
• No users or processes rely on it (even rarely)
• You can log occurrences over 30–90 days to be sure.

Option A – Remove the unused proxy addresses

Use PowerShell:

Set-Mailbox -Identity <User> -EmailAddresses @{remove="smtp:email address removed for privacy reasons"}

Option B Archive the Unused Proxy Addresses