Blue Folder

INSTALL GUIDE · FLY.IO

Blue Folder Mail on Fly.io

Managed hosting, no server to run. The repo ships a fly.toml that mounts a volume at /data and health-checks /_health.

Good fit
Fly gives you a persistent volume, so the default local-disk storage works as-is. Inbound mail is a webhook — Fly won't run an MTA for you.

Prerequisites

Deploy

  1. Launch without deploying yet
    fly launch --no-deploy
  2. Create the data volume
    fly volume create bfm_data -r iad -n 1 -s 1
    One 1 GB volume in your chosen region. fly.toml mounts it at /data.
  3. Set your secrets
    fly secrets set RESEND_API_KEY=... \
      INBOUND_SECRET=$(openssl rand -hex 24)

    Add BASIC_AUTH_USER / BASIC_AUTH_PASS here too for a login.

  4. Deploy
    fly deploy

    Open the app URL, create your mailbox and save the backup password.

Storage & sending

Receiving mail — the honest part

Recommended — webhook

Point a provider (Mailgun, SendGrid, Postal, Resend inbound) at https://your-app.fly.dev/_inbound with your INBOUND_SECRET as the x-inbound-secret header or ?secret=…, forwarding full raw MIME.

Fly is a container platform, not a mail host — don't try to run the built-in SMTP MTA here. The webhook is the path.

HTTPS & the front door

TLS on your *.fly.dev URL (and custom domains via fly certs) is automatic. Add a login before putting real mail in it — set BASIC_AUTH_USER / BASIC_AUTH_PASS as secrets.

Blue Folder Mail on Fly.io — a volume, three secrets, one deploy. Full reference: DEPLOY.md. Other platforms →