A locally-installed SMTP gateway that lets older scanners, copiers and multifunction devices send scan-to-email through Google Workspace or Microsoft 365, even though those devices only support legacy basic-auth SMTP. ScanTransit sits on your network, accepts the old-style SMTP connection from the device, and relays the message out using modern OAuth authentication, so you can keep using existing hardware after Google and Microsoft retire basic auth.
Features
- Accepts legacy basic-auth SMTP from scanners, copiers and MFDs
- Relays outbound mail via OAuth 2.0 to Google Workspace or Microsoft 365
- Runs locally on your network – no third-party mail relay
- One-time purchase, no subscription
- 7-day free trial
- Licensed via an ECC-encrypted serial number
Setup
- Install ScanTransit on a Mac that stays on your network, and approve the one-time background service prompt.
- Sign in with the Google Workspace or Microsoft 365 mailbox you want scans sent from.
- Set a device username and password in Settings, then point your scanner or copier's SMTP settings at the Mac.
- Send a test email from the ScanTransit app to confirm delivery before you walk back to the device.
Security
- Runs entirely on your own Mac – no third-party server ever sees your scans or your mailbox credentials.
- Devices authenticate with a dedicated username and password, stored bcrypt-hashed rather than in plain text.
- Your mailbox sign-in uses OAuth, with tokens stored in a root-only, encrypted location and never exposed to the network.
- Not an open relay – outbound mail can only be sent as the one mailbox you've signed in with.
- Supports plain SMTP, STARTTLS and implicit TLS, so you can match whatever encryption your device supports.
- An optional IP allowlist restricts which devices on your network are permitted to submit scans.