Glossary
Proxy Address
By Emil Björk · Microsoft ecosystem consultant, Gothenburg
An alternative email address routed to the same Exchange mailbox, configured as a secondary SMTP alias.
A proxy address in Exchange Online is an alternative email address routed to the same mailbox — typically a secondary SMTP alias on top of the user's primary address. A user can have many proxy addresses for handling email under different identities: [email protected] (primary) plus [email protected], [email protected] (from an acquisition), [email protected] (vanity), all delivered to the same mailbox. Managed in Exchange Admin Center or PowerShell (Set-Mailbox -EmailAddresses). The primary address gets used on outbound mail; proxies accept inbound. Distinct from forwarding (which sends mail elsewhere) — proxy addresses keep mail in the same mailbox.