Integration · MinIO
Back up email to MinIO — automatically.
Forward any email to your private InboxBucket address and the original .eml is written to a MinIO bucket on hardware you run — your homelab, your VPS, your rack. Self-hosted email backup, taken to its logical end.
Free plan available · No credit card required
- From:
- Acme Billing <[email protected]>
- To:
- [email protected]
- Subject:
- Invoice #4471 — June services
- Files:
- invoice-4471.pdf
s3://your-bucket/inboxbucket/2026/07/0714__invoice-4471__acme-billing.eml
✓ stored · 84 KB · original MIME
Why back up to MinIO
Your archive, on disks you can point at.
Ownership all the way down
Every InboxBucket destination puts your mail in storage you control. MinIO removes the last middleman: not a bucket in your name at someone's cloud, but files on machines you administer.
The S3 API, minus the cloud
MinIO speaks S3, so InboxBucket writes to it with the same connector it uses for AWS — an endpoint, a key, a bucket. Nothing about your setup has to change to receive an email archive.
Your policies, not a provider's
Versioning, replication, encryption, retention — all configured by you, on your terms. And there's no per-gigabyte bill: keeping twenty years of mail costs whatever your disks already cost.
How it works
Point it at your server, then forward.
Pick MinIO, add your server
Choose the MinIO tile in InboxBucket and enter your endpoint, bucket, and an access key and secret (details on the right).
Get your address
You receive a private inbound address that only receives mail:
[email protected]Forward anything
Forward one message by hand or set an auto-forward rule; seconds later the original .eml sits on your own disks.
What you'll need to connect
- Endpoint
- your server's public S3 API URL, e.g. https://minio.example.com
- Region
- us-east-1 (MinIO's default unless you changed it)
- Access key + secret
- created in the MinIO Console under Access Keys
- Bucket
- your backup bucket name
One requirement: InboxBucket is a hosted service, so your endpoint must be reachable from the public internet over HTTPS. Private IPs, localhost, and LAN-only hostnames are rejected at connect time — a homelab works fine behind a reverse proxy with TLS and a public DNS name.
Path-style addressing is handled automatically. MinIO speaks the same API as Amazon S3, so it uses the same connector — just aimed at your server.
The access we ask for
A key you mint, on a server you run.
You create the access key yourself and attach a policy that allows object writes on just your backup bucket — MinIO's IAM-style policies make that a few lines of JSON. The key InboxBucket holds can't list, read, or touch anything else on the server, and we store it encrypted at rest with AES-256-GCM.
We're the pipe, not the vault. Mail passes through us only on its way to your server; what we keep is the metadata behind your dashboard — sender, subject, date, status — never the messages. Delete the key on your MinIO anytime, and every .eml already written stays exactly where it is: on your disks.
- Scoped to one bucket by a policy you wrote yourself
- Credentials stored encrypted at rest (AES-256-GCM)
- Delete the key anytime — your .eml files stay on your disks
The details
Built like a backup should be.
The raw message, kept raw
Each email lands as a .eml file — the untouched RFC 822 bytes, headers and attachments included. Open it in any mail client, or in a text editor on the box itself.
Attachments land whole
Big files go over S3 multipart, which MinIO supports natively — so a 40 MB contract arrives as one complete object, not a failed request.
Retries can't double-write
Mail servers retry and people forward twice. Deduplication on Message-ID guarantees each message becomes exactly one object on your disks.
Failures are visible
If your server is down for an hour, nothing is lost: failed writes queue and retry, with status in your dashboard until every message has landed.
An allowlist for scraped addresses
Inbound addresses attract spam eventually. A per-sender allowlist means only mail from senders you've approved is ever written to your bucket.
No lock-in, in either direction
An open format on your own metal. Stop using InboxBucket and every .eml stays readable; outgrow MinIO and the archive moves with one copy command.
FAQ
MinIO backup, answered.
Can InboxBucket reach my homelab MinIO?
Yes, with one hard requirement: InboxBucket is a hosted service, so it can only write to a MinIO endpoint that is reachable from the public internet over HTTPS. Private IPs, localhost, and LAN-only hostnames are rejected at connect time. A homelab works fine behind a reverse proxy — Caddy, nginx, or Traefik with a TLS certificate and a public DNS name pointing at your MinIO S3 port is all it takes.
What endpoint and region do I use for MinIO?
The endpoint is your server's public S3 API URL — for example https://minio.example.com — not the console URL. The region is us-east-1, MinIO's default, unless you set a different one via MINIO_REGION or the site region config. InboxBucket handles path-style addressing automatically, so a plain hostname works.
What credentials should I create for InboxBucket?
An access key and secret scoped to just your backup bucket. In the MinIO Console, open Access Keys and create a key with a restricted policy that allows object writes only on your backup bucket (resources arn:aws:s3:::your-bucket and arn:aws:s3:::your-bucket/*). Note that recent MinIO community releases removed key management from the web console — there, create the key with mc admin accesskey create and pass the same policy inline. Either way, the key can't touch anything else on the server.
Is backing up email to MinIO the same as Amazon S3?
Technically yes — MinIO implements the S3 API, so InboxBucket uses the exact same connector, pointed at your endpoint instead of Amazon's. The difference is who runs the hardware. With the Amazon S3 setup you rent durability from AWS; with MinIO the disks, the retention rules, and the bill are yours.
What format are the backups in?
Every email is stored as a .eml file — the standard RFC 822 message with headers, body, and attachments in one portable file. Combined with self-hosted storage, that means zero lock-in on either side: drop InboxBucket and the files stay readable forever, or move off MinIO and the archive follows with a single copy.
Is MinIO email backup free?
InboxBucket's Free plan includes 100 emails per month and one storage connection, so you can archive to MinIO without paying anything; the Lifetime plan is a one-time $79. On the storage side there's no per-gigabyte bill at all — MinIO is software you run yourself, so the only cost is hardware you already own.
Free plan · No credit card
Put your email on your own hardware.
Add your MinIO, get your address, and the next email you forward is written to a bucket on machines you run — nobody else's cloud in the loop.
Add your MinIO bucket