INSTALL GUIDE · RENDER

Blue Folder Mail on Render

Managed hosting from a Blueprint. The repo ships render.yaml with a 1 GB persistent disk at /data and a /_health check — so storage survives restarts out of the box.

← All guides Deploy Inbound email

Good fit

The Blueprint already includes the persistent disk, so the default local-disk storage just works. Inbound mail is a webhook.

Deploy the Blueprint

New → Blueprint In the Render dashboard, create a Blueprint pointing at your fork. Render reads render.yaml and builds the included Dockerfile.
Fill in the secrets
The Blueprint marks the sensitive vars as sync:false, so Render prompts for them. Set RESEND_API_KEY and a random INBOUND_SECRET (openssl rand -hex 24), and ideally BASIC_AUTH_USER / BASIC_AUTH_PASS.
Create your mailbox
Open the service URL, generate your key and save the backup password, then add your domains in Settings.

The 1 GB disk at /data holds the SQLite index and sealed blobs. For more headroom, raise the disk size or set STORAGE_BACKEND=s3 for blobs and keep the index on the disk.

Storage & sending

Storage — the persistent disk at /data by default; or S3 for blobs via STORAGE_BACKEND=s3 and the S3_* vars. Sealed ciphertext only.
Sending — verify your domains at resend.com; the key is set as a Blueprint secret.

Receiving mail — the honest part

Recommended — webhook

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

Render is a web-service host, not a mail host — don't run the built-in SMTP MTA here. Use the webhook.

HTTPS & the front door

TLS on your *.onrender.com URL and custom domains is automatic. Add a login before adding real mail — set BASIC_AUTH_USER / BASIC_AUTH_PASS as env vars.

Blue Folder Mail on Render — a Blueprint, a disk, two secrets. Full reference: DEPLOY.md. Other platforms →