Deployment path

1. 1

   Baseline & DNS audit

   Snapshot of OVH records, mail flow mapped, deliverability measured before anything moved.

2. 2

   Stalwart on k3s

   SMTP/IMAP on a single node with PostgreSQL storage, TLS from Caddy, backups from day one.

3. 3

   Authentication

   SPF, DKIM, DMARC and MTA-STS configured and verified — mail-tester went to 10/10.

4. 4

   Campaigns & webmail

   Listmonk for newsletters, Roundcube for the team, FreeScout as the helpdesk — one namespace.

5. 5

   Automation

   A CronJob syncs HubSpot contacts every two hours; the OVH updater rewrites DNS after IP changes.

6. 6

   SMS gateway

   A SerwerSMS-powered module: campaigns by Listmonk segments, STOP handled automatically, delivery reports and balance alerts.

7. 7

   Jobs connector

   Airborn Jobs plugged in over a signed HTTPS contract — idempotent sends, delivery statuses and inbound replies without another vendor panel.

8. 8

   Telephony — Play VPBX

   Call history, click-to-call from the client card, missed-call callbacks and live call events — four stages shipped in two days.

9. 9

   One client card

   HubSpot ⋈ Listmonk grew to 17,700 contacts on a single CRM card: every e-mail, SMS, call and support thread in one timeline.

10. 10

    Handover & managed operations

    Docs, runbooks and training for the team; since October 2026 the GitOps canon, Argo CD and monitoring run by ProdMedia — changes ship as commits, alerts watch every channel.

Proof, not promises