Sender Accounts Overview

Sender accounts are email addresses used to send your ColdSend campaigns. ColdSend supports two main infrastructure types: ColdSend Native (managed) and SMTP/BYOC (bring your own credentials).

Unlike the old single-endpoint model, sender accounts are now created via type-specific endpoints: POST /sender-accounts/coldsend-native for managed accounts and POST /sender-accounts/smtp for SMTP accounts.

Account Types

ColdSend Native

Managed email infrastructure provided by ColdSend for optimal deliverability and simplified setup.

Feature	Description
Automatic Setup	No SMTP/IMAP configuration needed
Deliverability Optimization	ColdSend manages domain reputation
Bounce Handling	Automatic bounce processing via Azure Communication Services
Reply Tracking	Native integration via Mailcow

Endpoint: POST /api/public/v1/sender-accounts/coldsend-native

import requests

response = requests.post(
    "https://api.coldsend.pro/api/public/v1/sender-accounts/coldsend-native",
    headers={"X-API-Key": api_key},
    json={
        "domain_id": "550e8400-e29b-41d4-a716-446655440000",
        "email_prefix": "john",
        "display_name": "John Smith from Company"
    }
)

ColdSend Native inboxes are created on domains already managed by your ColdSend workspace. You specify a domain_id and an email prefix (e.g., john → john@yourdomain.com).

Bulk creation is also supported via POST /api/public/v1/sender-accounts/coldsend-native/bulk:

response = requests.post(
    "https://api.coldsend.pro/api/public/v1/sender-accounts/coldsend-native/bulk",
    headers={"X-API-Key": api_key},
    json={
        "domain_id": "550e8400-e29b-41d4-a716-446655440000",
        "inboxes": [
            {"email_prefix": "john", "display_name": "John Smith"},
            {"email_prefix": "sales", "display_name": "Sales Team"}
        ]
    }
)

SMTP / BYOC (Bring Your Own Credentials)

Use your existing email accounts with custom SMTP/IMAP settings. Supported provider types: GOOGLE_WORKSPACE, OUTLOOK_365, and CUSTOM_SMTP. Endpoint: POST /api/public/v1/sender-accounts/smtp

response = requests.post(
    "https://api.coldsend.pro/api/public/v1/sender-accounts/smtp",
    headers={"X-API-Key": api_key},
    json={
        "email_address": "outreach@company.com",
        "display_name": "John Smith from Company",
        "inbox_type": "GOOGLE_WORKSPACE",
        "daily_limit": 50,
        "smtp_host": "smtp.gmail.com",
        "smtp_port": 587,
        "smtp_username": "outreach@company.com",
        "smtp_password": "your-app-password",
        "smtp_use_tls": True,
        "imap_host": "imap.gmail.com",
        "imap_port": 993,
        "imap_username": "outreach@company.com",
        "imap_password": "your-app-password",
        "imap_use_ssl": True
    }
)

Use app-specific passwords, not your main account password. For Gmail, generate one at Google Account → Security → App Passwords.

Provider max daily limits:

Provider	Max Daily Limit
`GOOGLE_WORKSPACE`	2,000
`OUTLOOK_365`	5,000
`CUSTOM_SMTP`	100,000

Bulk SMTP creation is supported via POST /api/public/v1/sender-accounts/smtp/bulk. Each inbox’s SMTP/IMAP connections are tested asynchronously. The response includes a job_id you can poll at GET /api/public/v1/sender-accounts/smtp/bulk/{job_id}/progress.

response = requests.post(
    "https://api.coldsend.pro/api/public/v1/sender-accounts/smtp/bulk",
    headers={"X-API-Key": api_key},
    json={
        "inboxes": [
            {
                "email_address": "outreach@company.com",
                "display_name": "Outreach Team",
                "inbox_type": "GOOGLE_WORKSPACE",
                "daily_limit": 50,
                "smtp_host": "smtp.gmail.com",
                "smtp_port": 587,
                "smtp_username": "outreach@company.com",
                "smtp_password": "your-app-password",
                "smtp_use_tls": True,
                "imap_host": "imap.gmail.com",
                "imap_port": 993,
                "imap_username": "outreach@company.com",
                "imap_password": "your-app-password",
                "imap_use_ssl": True
            }
        ]
    }
)
job_id = response.json()["job_id"]

# Poll for progress
import time
while True:
    progress = requests.get(
        f"https://api.coldsend.pro/api/public/v1/sender-accounts/smtp/bulk/{job_id}/progress",
        headers={"X-API-Key": api_key}
    ).json()
    if progress["status"] in ("COMPLETED", "FAILED"):
        break
    time.sleep(3)

Bulk Delete Sender Accounts

POST /api/public/v1/sender-accounts/bulk/delete Delete up to 100 sender accounts in a single async job. The request returns immediately with a job_id; poll the progress endpoint to track completion.

response = requests.post(
    "https://api.coldsend.pro/api/public/v1/sender-accounts/bulk/delete",
    headers={"X-API-Key": api_key},
    json={
        "inbox_ids": [
            "750e8400-e29b-41d4-a716-446655440000",
            "850e8400-e29b-41d4-a716-446655440001"
        ]
    }
)
job_id = response.json()["job_id"]

GET /api/public/v1/sender-accounts/bulk/delete/{job_id}/progress Poll this endpoint to track bulk delete progress:

progress = requests.get(
    f"https://api.coldsend.pro/api/public/v1/sender-accounts/bulk/delete/{job_id}/progress",
    headers={"X-API-Key": api_key}
).json()
print(progress["status"], progress["completed"], "/", progress["total"])

Deleting a sender account removes it from all campaigns it was assigned to. Accounts actively sending emails in a running campaign should be removed from that campaign first.

API Endpoints

Method	Endpoint	Description
GET	`/sender-accounts`	List all sender accounts (paginated, filterable)
GET	`/sender-accounts/{inbox_id}`	Get detailed sender account info
DELETE	`/sender-accounts/{inbox_id}`	Remove a sender account
POST	`/sender-accounts/coldsend-native`	Create a ColdSend Native inbox
POST	`/sender-accounts/coldsend-native/bulk`	Bulk create ColdSend Native inboxes (max 100)
POST	`/sender-accounts/smtp`	Create an SMTP inbox (BYOC)
POST	`/sender-accounts/smtp/bulk`	Bulk create SMTP inboxes (max 100, async)
GET	`/sender-accounts/smtp/bulk/{job_id}/progress`	Track bulk SMTP job progress
POST	`/sender-accounts/bulk/delete`	Bulk delete sender accounts (async)
GET	`/sender-accounts/bulk/delete/{job_id}/progress`	Track bulk delete job progress
POST	`/sender-accounts/{inbox_id}/test-email`	Send a test email
GET	`/sender-accounts/quotas`	Get per-inbox daily quota state for a campaign
GET	`/sender-accounts/daily-usage`	Get daily send counts for all inboxes in team

List & Filter Sender Accounts

GET /api/public/v1/sender-accounts supports filtering and pagination:

response = requests.get(
    "https://api.coldsend.pro/api/public/v1/sender-accounts?inbox_type=GOOGLE_WORKSPACE&status=ACTIVE&page=1&limit=20",
    headers={"X-API-Key": api_key}
)

Query Parameters

Parameter	Description
`page`	Page number (1-based, default: 1)
`limit`	Items per page (1-100, default: 20)
`inbox_type`	Filter by type: `COLDSEND`, `GOOGLE_WORKSPACE`, `OUTLOOK_365`, `CUSTOM_SMTP`
`status`	Filter by status: `ACTIVE`, `PAUSED`, `DISABLED`
`search`	Search by email address
`sort_by`	Sort field: `email_address`, `inbox_type`, `created_at`, `health_score`
`sort_order`	Sort direction: `asc`, `desc`

Response Format

{
  "success": true,
  "message": "Retrieved 3 sender accounts",
  "sender_accounts": [
    {
      "inbox_id": "750e8400-e29b-41d4-a716-446655440000",
      "email_address": "john@company.com",
      "display_name": "John Smith",
      "inbox_type": "GOOGLE_WORKSPACE",
      "overall_status": "ACTIVE",
      "daily_limit": 50,
      "emails_sent_today": 12,
      "health_score": 95.0,
      "created_at": "2024-01-15T10:30:00Z"
    }
  ],
  "pagination": {
    "page": 1,
    "limit": 20,
    "total": 3,
    "pages": 1,
    "has_next": false,
    "has_prev": false
  }
}

Account Status

Status	Description
ACTIVE	Ready to use in campaigns
PAUSED	Temporarily disabled, can be reactivated
DISABLED	Cannot be used — may require re-authentication

Inbox Types

The API uses these inbox_type values consistently:

Value	Description
`COLDSEND`	ColdSend Native managed inbox
`GOOGLE_WORKSPACE`	Google Workspace via SMTP/IMAP
`OUTLOOK_365`	Microsoft 365 via SMTP/IMAP
`CUSTOM_SMTP`	Any custom SMTP provider

Next Steps

Provider Configuration

Detailed SMTP setup guides for Google Workspace, Microsoft 365, and custom providers.

Campaigns Overview

Learn how to assign sender accounts to campaigns.

Getting Started

Authentication

Campaigns

Sender Accounts

Domains

Leads

Replies

Analytics

Reference

Compliance

Sender Accounts Overview

Account Types

ColdSend Native

SMTP / BYOC (Bring Your Own Credentials)

Bulk Delete Sender Accounts

API Endpoints

List & Filter Sender Accounts

Query Parameters

Response Format

Account Status

Inbox Types

Next Steps

Provider Configuration

Campaigns Overview

​Account Types

​ColdSend Native

​SMTP / BYOC (Bring Your Own Credentials)

​Bulk Delete Sender Accounts

​API Endpoints

​List & Filter Sender Accounts

​Query Parameters

​Response Format

​Account Status

​Inbox Types

​Next Steps

Provider Configuration

Campaigns Overview

Account Types

ColdSend Native

SMTP / BYOC (Bring Your Own Credentials)

Bulk Delete Sender Accounts

API Endpoints

List & Filter Sender Accounts

Query Parameters

Response Format

Account Status

Inbox Types

Next Steps