factory/vibe/guidebooks/cms/zoho-email.md

[vibe](../../README.md) > [Guidebooks](../README.md) > [CMS](README.md) > **Zoho email**

# Zoho email

> **Status:** ✅ Active
> **Last Updated:** 2026-06-23
> **Upstream:** [CMS](README.md) · [Cloudflare](cloudflare.md)
> **Downstream:** [secrets-and-vault concept](../lab-ecosystem/secrets-and-vault.md)
> **Related:** [lab-ecosystem 03 · cms](../lab-ecosystem/03-cms.md) · [tofu CI flow](../factory-provisioning/opentofu/ci-apply-flow.md) · [safe-env ADR](../../ADR/0001-safe-prod-like-environment.md) · [safe-env PRD](../../PRD/safe-prod-like-environment/README.md)

Email for **arcodange.fr** is hosted at **Zoho Mail (EU region)** and provisioned *entirely from OpenTofu*. There is no Zoho web-console click-ops in the steady state: the same `tofu apply` that owns the Cloudflare zone also drives the Zoho REST API to read the organization, publish the DNS records mail delivery depends on, and create one mailbox alias + one Inbox sub-folder per address. This page lives under [`cms/cloudflare/zoho/`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho), a sub-module of the [Cloudflare](cloudflare.md) tofu root.

> [!CAUTION]
> **DNS/email changes here are high-stakes and slow to fail.** A wrong MX, SPF, DKIM, or DMARC record silently degrades or breaks `arcodange.fr` deliverability for **days** — receivers cache TTLs, reputation decays, and there is no synchronous error to catch in CI. DMARC is published as **`p=reject`**, so a broken SPF/DKIM alignment means conforming receivers *drop* legitimate mail outright rather than quarantine it. This is a prime motivation for the **safe environment**: changes to this module must be validated **plan-only against a throwaway/clone zone**, never iterated directly against the live `arcodange.fr` zone. See the [safe-env ADR](../../ADR/0001-safe-prod-like-environment.md) and the [safe-env PRD](../../PRD/safe-prod-like-environment/README.md).

## How the module is wired

The Cloudflare root ([`cloudflare/iac.tf`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/iac.tf)) instantiates `module "zoho"`, passing it the live zone and domain plus the OAuth client credentials:

| Input | Source | Purpose |
|---|---|---|
| `domain_name` | `ovh_domain_name.arcodange_fr.domain_name` | the domain to manage (`arcodange.fr`) |
| `dns_zone_id` | `cloudflare_zone.arcodange_fr.id` | Cloudflare zone the DNS records land in |
| `zoho_client_id` | `var.ZOHO_CLIENT_ID` (Vault `kvv1/zoho/self_client`) | OAuth2 self-client id |
| `zoho_client_secret` | `var.ZOHO_CLIENT_SECRET` (Vault `kvv1/zoho/self_client`) | OAuth2 self-client secret |

In CI the secrets are injected by the `vault-action` step in [`.gitea/workflows/cloudflare.yaml`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/.gitea/workflows/cloudflare.yaml), which maps the whole `kvv1/zoho/self_client` KV-v1 secret into **both** the shell env (`ZOHO_*`, consumed by the helper scripts) and the tofu vars (`TF_VAR_ZOHO_*`, consumed by `config.tf`):

```
kvv1/zoho/self_client * | ZOHO_ ;
kvv1/zoho/self_client * | TF_VAR_ZOHO_ ;
```

## OAuth2: client-credentials flow

Zoho is a self-client (machine-to-machine) integration on the **EU** datacenter — every host is `*.zoho.eu` / `accounts.zoho.eu`. Authentication uses the OAuth2 **`client_credentials`** grant; there is no interactive user consent in the running flow (a commented device-code flow remains in [`.env`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/.env) as historical bootstrap).

The token is minted in [`config.tf`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/config.tf) via a `data "http"` POST to `https://accounts.zoho.eu/oauth/v2/token` with `grant_type=client_credentials` and the comma-joined scope list. The bearer is then folded into an `Authorization: Zoho-oauthtoken <token>` header (`local.auth_headers`) reused by every subsequent read.

| Scope | Access | Why it is needed |
|---|---|---|
| `ZohoMail.partner.organization.READ` | READ (org) | resolve the org **ZOID** |
| `ZohoMail.organization.accounts.READ` | READ (accounts) | find the super-admin **account id / zuid** |
| `ZohoMail.organization.accounts.UPDATE` | UPDATE (accounts) | add / remove email aliases |
| `ZohoMail.organization.domains.READ` | READ (domains) | fetch the domain verification code + DKIM public key |
| `ZohoMail.folders.ALL` | ALL (folders) | list and create per-alias Inbox sub-folders |

Lookup chain (each step feeds the next):

1. `GET https://mail.zoho.eu/api/organization` → `local.org`, from which `zoid` builds `local.api_prefix = https://mail.zoho.eu/api/organization/<zoid>`.
2. `GET {api_prefix}/domains/{domain_name}` ([`dns.tf`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/dns.tf)) → `local.domain`, exposing `CNAMEVerificationCode` and `dkimDetailList[0].publicKey`.
3. `GET {api_prefix}/accounts` ([`email_aliases.tf`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/email_aliases.tf)) → the single `iamUserRole == "super_admin"` account, giving its `accountId` and `zuid`.

## DNS records published on the Cloudflare zone

[`modules/zoho_mail_dns`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/modules/zoho_mail_dns) materialises every `cloudflare_dns_record` Zoho mail needs onto the live zone. The DKIM key and verification code are read live from the Zoho domain API (step 2 above) and passed in as module inputs, so the records always track what Zoho actually expects. All records use **TTL 3600** and apply to the apex (`@`) unless noted.

| Name | Type | Value | Purpose |
|---|---|---|---|
| `@` | TXT | `"zoho-verification=<CNAMEVerificationCode>.zmverify.zoho.eu"` | proves domain ownership to Zoho |
| `@` | MX | `mx.zoho.eu` (priority **10**) | primary inbound mail exchanger |
| `@` | MX | `mx2.zoho.eu` (priority **20**) | secondary mail exchanger |
| `@` | MX | `mx3.zoho.eu` (priority **50**) | tertiary mail exchanger |
| `@` | TXT | `"v=spf1 include:zohomail.eu ~all"` | SPF: authorise Zoho to send for the domain |
| `zmail._domainkey` | TXT | `"<dkim_public_key>"` (from `dkimDetailList[0].publicKey`) | DKIM public key for outbound signing |
| `_dmarc` | TXT | `"v=DMARC1; p=reject; rua=mailto:arcodange@gmail.com; ruf=mailto:arcodange@gmail.com; sp=reject; adkim=r; aspf=r; pct=100"` | DMARC policy: **reject** non-aligned mail, 100% coverage, aggregate+forensic reports to `arcodange@gmail.com` |
| `default._bimi` | TXT | `"v=BIMI1; l=https://arcodange.fr/.well-known/logo.svg; avp=brand;"` | BIMI: display the brand logo beside authenticated mail (created only when `bimi_logo_url != null`) |

> [!WARNING]
> The DMARC policy is the strictest tier: `p=reject` **and** `sp=reject` (subdomains) with relaxed alignment (`adkim=r`, `aspf=r`) and `pct=100`. There is no `quarantine` grace band — any message that fails both SPF *and* DKIM alignment is rejected by conforming receivers. Validate SPF/DKIM correctness in the safe environment before touching the live `_dmarc` or apex records.

## Email aliases

Seven addresses are defined as a single map in [`email_aliases.tf`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/email_aliases.tf) (`local.email_aliases`). Each is provisioned **twice** against the super-admin mailbox: as an **email alias** on the account, and as a matching **Inbox sub-folder** so mail to that address can be filtered into its own folder.

| Alias (`@arcodange.fr`) | Display name | Purpose |
|---|---|---|
| `bonjour` | `Service Bonjour` | commercial / sales |
| `bureaux` | `Bureaux Arcodange` | official bodies (URSSAF, administration) |
| `contact` | `Premier Contact` | website contact form |
| `helloworld` | `✅ Arcodange 🏹💻🪽` | social networks, newsletter |
| `analytics` | `Analytics 📊🔍` | social networks, newsletter |
| `books` | `Accounting 📒🧮` | accounting / bookkeeping |
| `abonnements` | `Abonnements 📱🤖` | subscriptions (phone, AI, services) |

Provisioning is *imperative-inside-declarative*: each alias is a `terraform_data` resource whose `triggers_replace` watches whether the alias/folder is already present, and whose `local-exec` provisioners shell out to [`zoho_api_call.sh`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/zoho_api_call.sh) on **create** and **destroy**:

1. **Alias create** — `PUT {api_prefix}/accounts/{zuid}` with `mode=addEmailAlias`, scope `ZohoMail.organization.accounts.UPDATE`; fails fast if the response contains `OPERATION_NOT_PERMITTED`.
2. **Alias destroy** — same endpoint with `mode=deleteEmailAlias` (the bare local-part, split off the `alias:display` key).
3. **Folder create** — `POST /api/accounts/{accountId}/folders` with `parentFolderId` = the resolved **Inbox** folder id, scope `ZohoMail.folders.ALL`.
4. **Folder destroy** — looks the folder id up by name, `DELETE`s it, then also sweeps the corresponding `/Trash/<name>` (or `/Trash/Inbox_<name>`) folder Zoho leaves behind.

> [!NOTE]
> `terraform_data` + `local-exec` is used because aliases and folders are Zoho-side mutations with no first-class Terraform provider. The `triggers_replace = { missing = !contains(...) }` guard makes the apply idempotent: the provisioner only re-runs when the alias/folder is genuinely absent, so a clean plan is a no-op rather than a re-create.

## Helper scripts

Both scripts live beside the tofu and are invoked from `local-exec`. They share the OAuth client env vars (`ZOHO_CLIENT_ID`, `ZOHO_CLIENT_SECRET`, `ZOHO_TOKEN_ENDPOINT`) injected from Vault.

| Script | Role |
|---|---|
| [`zoho_api_call.sh`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/zoho_api_call.sh) | Thin HTTP wrapper. Parses `--endpoint`, `-x=<METHOD>`, `--scope`, `--data_json` / `--data_url`, and `--fail_if_str_in_resp`; sources `zoho_gen_token.sh`, attaches the bearer header, `curl`s the call, fails if a sentinel string (e.g. `OPERATION_NOT_PERMITTED`) appears, and emits compact JSON via `jq`. |
| [`zoho_gen_token.sh`](https://gitea.arcodange.lab/arcodange-org/cms/src/branch/main/cloudflare/zoho/zoho_gen_token.sh) | OAuth token cache. `gen_zoho_token <scope>` returns a cached token from `/tmp/zoho_oauth_tokens.cache` when fresh, otherwise mints a new `client_credentials` token and stores it. |

`zoho_gen_token.sh` is **lock-based and TTL-bounded**:

- A mutex is taken by `mkdir /tmp/zoho_oauth_tokens.lock` (atomic dir creation), with up to 10 one-second retries, so concurrent `local-exec` provisioners don't corrupt the cache. The lock is released on every function exit via `trap`.
- Tokens are keyed by scope in `/tmp/zoho_oauth_tokens.cache` (file mode `600`). A token is reused only while younger than **3600 s (~1 h)**; `cleanup_cache` prunes expired entries on each call.
- The wrapper runs `cleanup_cache` before each request and re-traps it on `INT TERM EXIT`, so stale tokens never leak past their TTL.

## Cross-references

- **Parent tofu / zone & Pages:** [Cloudflare](cloudflare.md) — owns `cloudflare_zone.arcodange_fr` that this module writes records into, and the `vault-action` CI step that supplies the credentials.
- **Where these secrets come from:** [secrets-and-vault concept](../lab-ecosystem/secrets-and-vault.md) (`kvv1/zoho/self_client`).
- **How apply runs:** [tofu CI flow](../factory-provisioning/opentofu/ci-apply-flow.md).
- **Why a safe environment exists:** [safe-env ADR](../../ADR/0001-safe-prod-like-environment.md) · [safe-env PRD](../../PRD/safe-prod-like-environment/README.md).