Postfix transport_maps

Route recipient domains to different transports or next-hop destinations.

v2.4Updated 2026-07-20Production guidance
Production note: Back up configuration, run postfix check, and stage changes before reloading.

Purpose

transport_maps selects the delivery transport and optional next hop by recipient domain.

Configuration

transport_maps = hash:/etc/postfix/transport

# /etc/postfix/transport
example.net smtp:[relay.example.net]:25
.internal.example local:

postmap /etc/postfix/transport
postfix check
postfix reload

Lookup tests

postmap -q example.net hash:/etc/postfix/transport

Production notes

Use brackets to suppress MX lookup when routing to an explicit relay host. Rebuild indexed maps after edits.

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