ramon/mail-reply

Reply-by-email for Flarum: unique per-user/per-discussion Reply-To addresses plus inbound email processing (parse, strip quotes/signatures, post reply).

0.2.0-beta 2026-04-21 21:42 UTC

Requires

• flarum/core: ^2.0.0
• willdurand/email-reply-parser: ^2.9 || ^3.0

MIT

• Ramon Guilherme

• mail
• flarum
• inbound-email
• reply-by-email

README

Reply-by-email for Flarum 2, inspired by GitHub and Discourse.

What it does

1. Unique Reply-To per notification. When Flarum sends an email notification (new post, mention, etc.) this extension injects a header like:

   Reply-To: [e-mail]
   

   The token encodes the recipient user + the discussion and is HMAC-signed against a server secret, so it cannot be forged.

2. Inbound email processing. When the user replies to that email, your MTA (or an inbound provider like Mailgun/Postmark) forwards the message to:

   • POST /api/mail-reply/inbound (HTTP webhook, with a shared secret), or
   • php flarum mail-reply:process (STDIN pipe, for Postfix/Exim aliases).

   The extension verifies the token, strips quoted history and signatures, and creates a CommentPost on behalf of the original recipient.

Configure

Set these via the admin settings UI (Flarum settings repo keys):

Key	Description
ramon-mail-reply.domain	Domain for the synthetic Reply-To (e.g. reply.example.com). Leave blank to disable.
ramon-mail-reply.webhook_secret	Shared secret required in the X-Mail-Reply-Token header on inbound webhook calls.
ramon-mail-reply.secret	(Optional) HMAC key for tokens. Falls back to APP_KEY.
ramon-mail-reply.token_ttl_days	Token lifetime in days (default: 30).
ramon-mail-reply.strip_signatures	true to run the full reply parser (default), false to only trim quoted lines.

Mailgun / Postmark / SendGrid route

Point the inbound route at:

POST https://yourforum.tld/api/mail-reply/inbound
Header: X-Mail-Reply-Token: <same value as ramon-mail-reply.webhook_secret>

Postfix alias (STDIN pipe)

reply:   "|/usr/bin/php /var/www/flarum/flarum mail-reply:process"

Install

composer require ramon/mail-reply
php flarum migrate
php flarum extension:enable ramon-mail-reply

Admin panel

The extension ships with a small admin settings panel (domain, webhook secret, HMAC key, token TTL, signature stripping, "via email" badge toggle).

Forum badge

Posts created from an inbound email reply are flagged (posts.via_mail_reply) and rendered with a small "via email" badge next to the post author. The badge can be turned off from the admin settings page (Show "via email" badge on replies).

Build

cd js
npm install
npm run build

Outputs js/dist/admin.js and js/dist/forum.js; both are loaded automatically by extend.php.