Two-way transactional email. Send notifications, alerts, and receipts — receive replies and bounces via webhooks. mTLS authentication, DKIM signing, built-in DNS.
SMTP smtp.ataca.io:465
S: 220 rail SMTP relay
C: EHLO myservice
C: MAIL FROM:<noreply@ataca.io>
C: RCPT TO:<user@example.com>
C: DATA
C: Subject: Your order shipped
C: ...
C: .
S: 250 OK 01JA5X...
HTTP API POST /v1/send
curl -X POST https://smtp.ataca.io/v1/send \
--cert client.crt --key client.key \
-H "Content-Type: application/json" \
-d '{
"from": "noreply@ataca.io",
"to": ["user@example.com"],
"subject": "Your order shipped",
"body_text": "Your package is on the way."
}'
// Response:
{"id": "01JA5X...", "status": "queued"}
Inbound smtp.ataca.io:25
// Replies and bounces arrive on port 25 (STARTTLS)
// Rail delivers them to your app via webhook:
POST https://your-app.com/hooks/email
{
"message_id": "01KMT...",
"from": "user@gmail.com",
"to": ["noreply@ataca.io"],
"subject": "Re: Your order shipped",
"raw_message": "<base64>"
}