# Konsep — POP3 Drain cPanel → Mailcow (inbox tunggal)

> **Terakhir Diperbarui:** 2026-07-03  
> **Status:** Rencana arsitektur — **keputusan user**  
> **Konteks:** MX `geonet.co.id` tetap cPanel; inbox canonical di Mailcow `sync.geonet.co.id`

---

## Ringkasan keputusan

| Aspek | Rencana |
|-------|---------|
| MX `geonet.co.id` | Tetap cPanel (belum cutover) |
| Inbox cPanel | **Kosong** — hanya staging sementara |
| POP3 drain | VM/service tarik POP3 dari cPanel, **hapus** setelah sukses |
| Inbox canonical | Mailcow `sync.geonet.co.id` (IMAP) |
| Outlook user | IMAP + SMTP **hanya** `sync.geonet.co.id` |
| Zammad | IMAP + SMTP ke Mailcow (mailbox sama dengan user) |
| Mailcow host | `10.100.1.28` |

**Prinsip:** cPanel hanya pintu masuk internet; **semua orang baca/tulis email lewat Mailcow**.

---

## Diagram alur

```mermaid
flowchart TB
  subgraph internet [Internet]
    S[Pengirim / penerima balasan]
  end

  subgraph cpanel [cPanel — staging kosong]
    MX[MX geonet.co.id]
    STG[(Inbox cPanel\nkosong setelah POP3)]
  end

  subgraph vm [VM 10.100.1.28]
    FM[fetchmail / getmail\nPOP3 drain + delete]
    MC[Mailcow sync.geonet.co.id]
    MBX[(Inbox IMAP\ncanonical)]
  end

  subgraph clients [Klien]
    OL[Outlook user\nIMAP + SMTP]
    Z[Zammad\nIMAP + SMTP]
  end

  S -->|email baru| MX --> STG
  STG -->|POP3 :995\nhapus setelah OK| FM -->|SMTP inject :587| MC --> MBX
  MBX -->|IMAP :993| OL
  MBX -->|IMAP poll| Z
  OL -->|SMTP :587| MC
  Z -->|SMTP :587| MC
  MC -->|kirim ke internet| S
```

---

## Peran masing-masing komponen

### 1. cPanel (`mail.geonet.co.id`)

| Fungsi | Detail |
|--------|--------|
| MX record | Masih menunjuk ke hosting — email dari internet masuk sini dulu |
| Inbox | **Staging** — harus kosong setelah POP3 drain berjalan |
| User Outlook | **Tidak** connect ke cPanel lagi |
| POP3 | `mail.geonet.co.id:995` SSL — hanya untuk service VM |

### 2. VM — POP3 drain (fetchmail)

Service di server (bisa di VM yang sama dengan Mailcow), **bukan** di PC user.

| Setting | Nilai |
|---------|-------|
| Protokol sumber | POP3 SSL `:995` |
| Host | `mail.geonet.co.id` |
| User | `nama@geonet.co.id` (per mailbox) |
| Setelah sukses | **Hapus** dari cPanel (`fetchall` + tidak `keep`) |
| Tujuan | SMTP ke Mailcow `127.0.0.1:587` atau `sync.geonet.co.id:587` |
| Jadwal | Cron/systemd tiap **1–2 menit** |

**Contoh `fetchmailrc` (produksi di `/opt/fetchmail/fetchmailrc`):**

```
poll mail.geonet.co.id with proto POP3 port 995
  user "support@geonet.co.id" there with password "..." is "support@geonet.co.id" here
  ssl
  no sslcertck
  smtphost 127.0.0.1
  smtpname sync.geonet.co.id
  fetchall
  nokeep
```

> Password dengan `#` atau `$` harus di-escape (generate via Python `repr()`).  
> `ssl` harus **setelah** baris `user`, bukan sebelum.  
> `no sslcertck` — cert cPanel `*.idcloudhosting.cloud` ≠ `mail.geonet.co.id`.  
> SMTP inject ke Mailcow via `127.0.0.1:25` (tanpa auth).  
> Install: `scripts/install-fetchmail-support.sh` + systemd timer 2 menit.

### 3. Mailcow (`sync.geonet.co.id`)

| Fungsi | Detail |
|--------|--------|
| Hostname | `sync.geonet.co.id` |
| Inbox canonical | Semua pesan hidup di sini |
| Domain mailbox | Tambah `geonet.co.id` di Mailcow agar alamat tetap `user@geonet.co.id` |
| Dovecot IMAP | `:993` — Outlook & Zammad |
| Postfix SMTP | `:587` — kirim balasan |

### 4. Outlook user

Satu akun saja — **tidak** ada akun cPanel.

| Setting | Nilai |
|---------|-------|
| **Incoming** | IMAP |
| Server | `sync.geonet.co.id` |
| Port | `993` |
| Encryption | SSL/TLS |
| **Outgoing** | SMTP |
| Server | `sync.geonet.co.id` |
| Port | `587` (STARTTLS) atau `465` (SSL) |
| Auth | Ya — username = email penuh |
| Username | `nama@geonet.co.id` |

### 5. Zammad

Sama seperti Outlook — satu mailbox di Mailcow:

| Arah | Konfigurasi |
|------|-------------|
| Inbound | IMAP `sync.geonet.co.id:993` → `support@geonet.co.id` |
| Outbound | SMTP `sync.geonet.co.id:587` → `support@geonet.co.id` |

---

## Mengapa POP3 drain (bukan imapsync mirror)

| | imapsync (salin) | POP3 drain (pilihan user) |
|--|------------------|---------------------------|
| Inbox cPanel | Masih berisi salinan | **Kosong** |
| Sumber kebenaran | Dua tempat | **Satu** — Mailcow saja |
| Outlook connect ke | Harus Mailcow saja juga | Mailcow saja ✅ |
| Risiko duplikat | Ada jika lupa aturan | Rendah |

Cocok dengan tujuan: **user hanya tahu `sync.geonet.co.id`**, cPanel tidak dipakai sehari-hari.

---

## SPF / DKIM outbound (penting)

Balasan dari Mailcow dengan `From: user@geonet.co.id` butuh DNS mengizinkan server `.102`:

| Record | Fase transisi | Fase akhir |
|--------|---------------|------------|
| SPF `geonet.co.id` | Tambah IP publik `.102` **atau** relay SMTP cPanel sebagai smarthost | Mailcow only |
| DKIM | Generate di Mailcow, publish TXT | Sama |
| DMARC | Opsional awal | Disarankan |

**Opsi jika belum siap SPF:**

- Mailcow **smarthost** → `sc138.idcloudhosting.cloud:465` untuk outbound `@geonet.co.id`
- Atau Zammad SMTP tetap hosting sementara, Outlook SMTP Mailcow (campuran — kurang ideal)

**Target user:** Outlook incoming **dan** outgoing `sync.geonet.co.id` → siapkan SPF/DKIM `geonet.co.id` untuk IP Mailcow.

---

## Multi-mailbox

Setiap `user@geonet.co.id` di cPanel perlu:

1. Entry fetchmail POP3 sendiri (atau satu script loop)
2. Mailbox matching di Mailcow
3. Outlook user connect ke Mailcow

Contoh tim:

| cPanel POP3 | Mailcow mailbox | Klien |
|-------------|-----------------|-------|
| `support@geonet.co.id` | `support@geonet.co.id` | Zammad + Outlook IT |
| `info@geonet.co.id` | `info@geonet.co.id` | Outlook admin |
| `nama@geonet.co.id` | `nama@geonet.co.id` | Outlook user |

---

## Risiko & mitigasi

| Risiko | Dampak | Mitigasi |
|--------|--------|----------|
| fetchmail mati | Email menumpuk di cPanel, user tidak lihat | Monitor cron + alert (Uptime Kuma / script) |
| Latency 1–2 menit | Email tidak instant di Outlook | Kurangi interval cron; terima sebagai trade-off |
| POP3 gagal mid-batch | Pesan bisa hilang jika delete sebelum SMTP OK | Pakai fetchmail `nokeep` hanya setelah SMTP sukses (default behavior) |
| Port 25 blokir | Outbound Mailcow gagal | Smarthost cPanel atau port 587 |
| VM `.102` down | Semua mail flow stop | HA / backup VM; monitor |

---

## Perbedaan dengan pola Thunderbird manual

| | Thunderbird di PC | fetchmail di VM |
|--|-------------------|-----------------|
| POP3 drain | User PC harus nyala | Server 24/7 |
| Deliver ke Mailcow | Manual / filter | Otomatis SMTP inject |
| Outlook user | Hanya IMAP Mailcow | Sama ✅ |

Thunderbird **tidak** dipakai untuk bridge — hanya Outlook (atau client lain) ke Mailcow.

---

## Roadmap

| Tahap | Aksi |
|-------|------|
| **1** | Install Mailcow di VM `.102`, hostname `sync.geonet.co.id` |
| **2** | Tambah domain `geonet.co.id` + buat mailbox |
| **3** | Deploy fetchmail POP3 drain per mailbox |
| **4** | Kosongkan inbox cPanel (tes drain) |
| **5** | Konfigurasi Outlook user → IMAP/SMTP Mailcow |
| **6** | Zammad IMAP + SMTP Mailcow |
| **7** | SPF/DKIM untuk outbound `@geonet.co.id` |
| **8** | Stabil 2–4 minggu |
| **9** | Cutover MX → `sync.geonet.co.id`, matikan fetchmail |

---

## Checklist

- [ ] VM `10.100.1.28` provisioned (16 vCPU, 32 GB, 2×512 GB)
- [ ] DNS A `sync.geonet.co.id` → IP publik
- [ ] Mailcow + domain `geonet.co.id`
- [x] fetchmail + timer 2 menit (`support@geonet.co.id`) — `scripts/install-fetchmail-support.sh`
- [ ] Verifikasi inbox cPanel kosong setelah drain
- [ ] Outlook: IMAP+SMTP `sync.geonet.co.id`
- [ ] Zammad channel email → Mailcow
- [ ] SPF/DKIM `geonet.co.id`
- [ ] Monitoring fetchmail

---

## Referensi

- `Mailcow/docs/environment.md`
- `Zammad/docs/notes/email-geonet-co-id.md`
- `fetchmail` man: https://www.fetchmail.info/