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ADR 0005: Mailjet HTTP API on one account for all email

  • Status: Accepted
  • Date: 2026-09-11 (documents the post-migration fix, September 2026)

Context

DigitalOcean blocks outbound SMTP ports on droplets, so classic SMTP transport silently times out. Multiple apps (portal, demo shops, uptime monitor) need transactional email, and scattering providers means scattering deliverability reputation and sender validation.

Decision

All email sends through the Mailjet HTTP API (rides on 443) using the single Keferboeck account (key prefix 453c). The sender domain keferboeck.com is validated wildcard (SPF, DKIM and the domain ownership TXT record live in DigitalOcean DNS), so any *@keferboeck.com sender works without per-address validation.

Consequences

One deliverability reputation to protect, one place to check the send log. New sender addresses need zero setup. Any non-keferboeck.com sender domain (e.g. growcentric.ai) must be validated in the same account before use, or mail is accepted and silently dropped — that failure mode is documented in the incident log.