Create an SMTP sending account
curl --request POST \
--url https://app.sendmux.ai/api/v1/providers \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"name": "Transactional SMTP",
"smtp_host": "smtp.example.com",
"smtp_password": "smtp-password",
"smtp_port": 587,
"smtp_protocol": "starttls",
"smtp_username": "api-user"
}
'import requests
url = "https://app.sendmux.ai/api/v1/providers"
payload = {
"name": "Transactional SMTP",
"smtp_host": "smtp.example.com",
"smtp_password": "smtp-password",
"smtp_port": 587,
"smtp_protocol": "starttls",
"smtp_username": "api-user"
}
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({
name: 'Transactional SMTP',
smtp_host: 'smtp.example.com',
smtp_password: 'smtp-password',
smtp_port: 587,
smtp_protocol: 'starttls',
smtp_username: 'api-user'
})
};
fetch('https://app.sendmux.ai/api/v1/providers', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://app.sendmux.ai/api/v1/providers"
payload := strings.NewReader("{\n \"name\": \"Transactional SMTP\",\n \"smtp_host\": \"smtp.example.com\",\n \"smtp_password\": \"smtp-password\",\n \"smtp_port\": 587,\n \"smtp_protocol\": \"starttls\",\n \"smtp_username\": \"api-user\"\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}{
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": true,
"data": {
"allowed_actions": {
"activate": true,
"deactivate": true,
"delete": true,
"test": true,
"update": true
},
"created_at": "2026-05-25T02:18:00Z",
"from_email": "<string>",
"from_name": "<string>",
"has_refresh_token": true,
"has_smtp_password": true,
"id": "dprov_clxxxxxxxxxxxxxxxxxxxxxxxxx",
"is_active": true,
"is_editable": true,
"is_shared": true,
"last_tested_at": "<string>",
"last_used_at": "<string>",
"name": "Transactional SMTP",
"oauth_email": "<string>",
"percentage": 100,
"quotas": {
"per_day": {
"max": 60,
"min": 60
},
"per_hour": {
"max": 60,
"min": 60
},
"per_minute": {
"max": 60,
"min": 60
},
"per_second": {
"max": 60,
"min": 60
}
},
"reply_to_email": "<string>",
"reply_to_name": "<string>",
"smtp_host": "<string>",
"smtp_port": 123,
"smtp_protocol": "<string>",
"smtp_username": "<string>",
"status": "active",
"status_reason": "<string>",
"tracking_domain": "<string>",
"type": "smtp",
"updated_at": "2026-05-25T02:18:00Z"
}
}{
"error": {
"code": "invalid_parameter",
"message": "<string>",
"retryable": false,
"doc_url": "<string>",
"errors": [
{
"code": "invalid_string",
"field": "recipient.email",
"message": "<string>"
}
],
"param": "<string>"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": false
}{
"error": {
"code": "invalid_parameter",
"message": "<string>",
"retryable": false,
"doc_url": "<string>",
"errors": [
{
"code": "invalid_string",
"field": "recipient.email",
"message": "<string>"
}
],
"param": "<string>"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": false
}{
"error": {
"code": "invalid_parameter",
"message": "<string>",
"retryable": false,
"doc_url": "<string>",
"errors": [
{
"code": "invalid_string",
"field": "recipient.email",
"message": "<string>"
}
],
"param": "<string>"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": false
}Sending accounts
Create an SMTP sending account
Creates a custom SMTP sending account. Supply an Idempotency-Key header to safely retry on network errors. The SMTP password is stored securely and is never returned.
POST
/
providers
Create an SMTP sending account
curl --request POST \
--url https://app.sendmux.ai/api/v1/providers \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"name": "Transactional SMTP",
"smtp_host": "smtp.example.com",
"smtp_password": "smtp-password",
"smtp_port": 587,
"smtp_protocol": "starttls",
"smtp_username": "api-user"
}
'import requests
url = "https://app.sendmux.ai/api/v1/providers"
payload = {
"name": "Transactional SMTP",
"smtp_host": "smtp.example.com",
"smtp_password": "smtp-password",
"smtp_port": 587,
"smtp_protocol": "starttls",
"smtp_username": "api-user"
}
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({
name: 'Transactional SMTP',
smtp_host: 'smtp.example.com',
smtp_password: 'smtp-password',
smtp_port: 587,
smtp_protocol: 'starttls',
smtp_username: 'api-user'
})
};
fetch('https://app.sendmux.ai/api/v1/providers', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://app.sendmux.ai/api/v1/providers"
payload := strings.NewReader("{\n \"name\": \"Transactional SMTP\",\n \"smtp_host\": \"smtp.example.com\",\n \"smtp_password\": \"smtp-password\",\n \"smtp_port\": 587,\n \"smtp_protocol\": \"starttls\",\n \"smtp_username\": \"api-user\"\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}{
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": true,
"data": {
"allowed_actions": {
"activate": true,
"deactivate": true,
"delete": true,
"test": true,
"update": true
},
"created_at": "2026-05-25T02:18:00Z",
"from_email": "<string>",
"from_name": "<string>",
"has_refresh_token": true,
"has_smtp_password": true,
"id": "dprov_clxxxxxxxxxxxxxxxxxxxxxxxxx",
"is_active": true,
"is_editable": true,
"is_shared": true,
"last_tested_at": "<string>",
"last_used_at": "<string>",
"name": "Transactional SMTP",
"oauth_email": "<string>",
"percentage": 100,
"quotas": {
"per_day": {
"max": 60,
"min": 60
},
"per_hour": {
"max": 60,
"min": 60
},
"per_minute": {
"max": 60,
"min": 60
},
"per_second": {
"max": 60,
"min": 60
}
},
"reply_to_email": "<string>",
"reply_to_name": "<string>",
"smtp_host": "<string>",
"smtp_port": 123,
"smtp_protocol": "<string>",
"smtp_username": "<string>",
"status": "active",
"status_reason": "<string>",
"tracking_domain": "<string>",
"type": "smtp",
"updated_at": "2026-05-25T02:18:00Z"
}
}{
"error": {
"code": "invalid_parameter",
"message": "<string>",
"retryable": false,
"doc_url": "<string>",
"errors": [
{
"code": "invalid_string",
"field": "recipient.email",
"message": "<string>"
}
],
"param": "<string>"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": false
}{
"error": {
"code": "invalid_parameter",
"message": "<string>",
"retryable": false,
"doc_url": "<string>",
"errors": [
{
"code": "invalid_string",
"field": "recipient.email",
"message": "<string>"
}
],
"param": "<string>"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": false
}{
"error": {
"code": "invalid_parameter",
"message": "<string>",
"retryable": false,
"doc_url": "<string>",
"errors": [
{
"code": "invalid_string",
"field": "recipient.email",
"message": "<string>"
}
],
"param": "<string>"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"ok": false
}Authorizations
Sendmux API key. Use a root API key for Management API routes, or a mailbox credential for Mailbox API routes. Obtain keys from the dashboard under API Keys.
Headers
Client-chosen unique key to safely retry the request. Cached for 24h per (team, endpoint, key). Different body with same key returns 409 idempotency_conflict.
Maximum string length:
255Example:
"providers-create-20260525-001"
Body
application/json
Required string length:
1 - 255Example:
"Transactional SMTP"
Required string length:
1 - 255Example:
"smtp.example.com"
Required string length:
1 - 500Example:
"smtp-password"
Required range:
1 <= x <= 65535Example:
587
Available options:
tls, ssl, none, starttls Example:
"starttls"
Required string length:
1 - 255Example:
"api-user"
Maximum string length:
255Example:
"sender@example.com"
Maximum string length:
255Example:
"Acme"
Required range:
0 <= x <= 100Example:
100
Hide child attributes
Hide child attributes
Quota value. Use a number for a fixed cap, a min/max range, or null to clear on PATCH.
Required range:
x > 0Quota value. Use a number for a fixed cap, a min/max range, or null to clear on PATCH.
Required range:
x > 0Quota value. Use a number for a fixed cap, a min/max range, or null to clear on PATCH.
Required range:
x > 0Quota value. Use a number for a fixed cap, a min/max range, or null to clear on PATCH.
Required range:
x > 0Maximum string length:
255Example:
"support@example.com"
Maximum string length:
255Example:
"Support"
Maximum string length:
255Example:
"click.example.com"
Response
Sending account created
Available options:
true Hide child attributes
Hide child attributes
ISO 8601 creation timestamp
Example:
"2026-05-25T02:18:00Z"
Default From email address.
Default From display name.
Whether an OAuth account has an active connection token.
Whether a custom SMTP password is stored.
Sending account public ID
Example:
"dprov_clxxxxxxxxxxxxxxxxxxxxxxxxx"
Whether this account is enabled for sending.
False when the account is platform-managed.
True for the team's shared Amazon SES account.
Last connection test timestamp.
Last send timestamp.
Display name
Example:
"Transactional SMTP"
Connected account email for OAuth accounts.
Routing weight percentage.
Example:
100
Hide child attributes
Hide child attributes
Default Reply-To email address.
Default Reply-To display name.
SMTP host for custom SMTP accounts.
SMTP port for custom SMTP accounts.
SMTP security mode.
SMTP username for custom SMTP accounts.
Current sending account status.
Available options:
active, inactive, error, pending Example:
"active"
Public-safe reason for the current status.
Custom tracking hostname.
Sending account type. amazon_ses is the shared managed account.
Available options:
smtp, gmail_api, outlook_api, amazon_ses Example:
"smtp"
ISO 8601 last update timestamp
Example:
"2026-05-25T02:18:00Z"
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