---
id: MAS-WP-0004
type: workplan
title: "MAS Postfix integration profile"
domain: communication
repo: mail-address-semantics
status: proposed
owner: claude
topic_slug: coulomb-social
created: "2026-10-18"
updated: "2026-10-18"
origin: residual
origin_ref: MAS-WP-0003
---

# MAS Postfix integration profile

Decision-gate outcome of MAS-WP-0002 (founder, 2026-10-18). MAS-WP-0003
showed that a default Postfix silently drops every P2 (`!`) address, and
that the correct relay configuration is not obvious
(`docs/experiment-review.md`, operational findings). Turn the working
setup in `deploy/railiance/entrypoint.sh` into a documented, tested
integration profile.

## Extract the profile

```task
id: MAS-WP-0004-T01
status: todo
priority: high
```

Write a standalone Postfix profile (main.cf/master.cf fragments plus
the relay regexp) for a MAS receiving domain:
- explicit `@DOMAIN` relay regexp, ending the restriction list in `reject`;
- `allow_untrusted_routing=yes`, `swap_bangpath=no` and `allow_percent_hack=no`;
- pipe to `mas-gateway`;
- optional authenticated relay with a send cap;
- null-sender discard.
Explain each setting and say why the stock config fails.

## Probe the profile

```task
id: MAS-WP-0004-T02
status: todo
priority: high
```

Extend `experiments/postfix-probe/` to run the profile against the full
address corpus. Include the relay negatives (`x@other`, `x!y@other`,
`a@other@DOMAIN`, `a@DOMAIN@other`) and P2 forms. Make it part of the test
suite where Docker is available.

## Exim notes

```task
id: MAS-WP-0004-T03
status: todo
priority: low
```

Check whether Exim has equivalent pitfalls for `!`/`%` local-parts and
record the needed settings. Build an Exim profile only if there is
demand.