Transactional email that lands.

Send password resets, receipts and alerts over a Mailgun- or Postmark-compatible HTTP API or plain SMTP. Your existing SDKs work by changing one base URL.

Create a free sandbox account Read the docs

Drop-in APIs

Mailgun /v3/{domain}/messages and Postmark /email endpoints, webhooks and suppression APIs. Point the SDK at https://mailportal.tos.llc.

SMTP relay

smtp.mailportal.tos.llc on port 2525 (STARTTLS) or 2465 (TLS). Works with WordPress, WHMCS, Laravel, Nodemailer and any mail client.

Authenticated by default

Per-domain 2048-bit DKIM, SPF, custom Return-Path for alignment, one-click unsubscribe headers.

Logs, events, webhooks

Per-recipient delivery status with the receiving server's response, opens, clicks, bounces and complaints, pushed to your webhook.