cURL request
POST /api/v1/bulk-taskscurl -X POST "https://emailcheckpro.com/api/v1/bulk-tasks" \
-H "X-API-Key: sk_your_api_key" \
-F service_type=email_batch \
-F file=@emails.txtBulk product email_batch
Email Bulk Deliverability Check
Upload a whole file of addresses, find out which ones can receive mail, and download the result when it finishes.
An add-on for whole large lists — for a handful of emailes the realtime check answers in the same request. Realtime check →
API contract
Two steps: submit the file, then check the task
Submitting returns a task id right away; check the task by that id and, once it succeeds, the response carries the result file download link. Each request is shown with its own response.
1. Submit the file
The task id comes back straight away with preparing set to true while the file is prepared in the background: invalid lines, duplicates and — for number tasks — numbers without a country code or from another country are removed and not charged. Balance is reserved for the submitted lines and settled on completion; the difference is refunded.
Response: task created
200 OK{
"code": 0,
"msg": "ok",
"data": {
"id": "3f9c2a7d8e4b4c1a9f0e6b2d5c8a7e13",
"product": "email_batch",
"status": "processing",
"submitted_lines": 1015,
"total": 1015,
"invalid_cnt": 0,
"no_code_cnt": 0,
"other_country_cnt": 0,
"duplicate_cnt": 0,
"preparing": true,
"created_at": "2026-09-08T09:30:00Z"
}
}2. Check the task
Poll by task id. Once preparation finishes, submitted_lines = total + invalid_cnt + no_code_cnt + other_country_cnt + duplicate_cnt, where total is what is checked and charged. A successful response carries the success and failure counts and the result file download link; a task refused during preparation is failed with reason_detail and refunded in full.
cURL request
GET /api/v1/bulk-tasks/{id}curl "https://emailcheckpro.com/api/v1/bulk-tasks/3f9c2a7d8e4b4c1a9f0e6b2d5c8a7e13" \
-H "X-API-Key: sk_your_api_key"Response: task finished
200 OK{
"code": 0,
"msg": "ok",
"data": {
"id": "3f9c2a7d8e4b4c1a9f0e6b2d5c8a7e13",
"product": "email_batch",
"status": "success",
"submitted_lines": 1015,
"total": 1000,
"invalid_cnt": 3,
"no_code_cnt": 0,
"other_country_cnt": 0,
"duplicate_cnt": 12,
"preparing": false,
"success_cnt": 990,
"failure_cnt": 10,
"result_url": "https://…/result.csv",
"created_at": "2026-09-08T09:30:00Z"
}
}How it runs
What happens to a bulk task
Bulk is not realtime made bigger — it is submit once, run in the background, collect later. You do not need to keep the page open; task state and results stay in your dashboard.
01Upload the file
A .txt or .csv with one email per line. It is streamed straight through; nothing is written to disk.
02Precheck and reserve
Obvious problems (an empty file, the wrong format, too few lines) are rejected on upload. Balance is then reserved and the file is prepared in the background: duplicate and invalid lines are removed and the provider scope is checked. A file that fails there ends as a failed task, refunded in full; otherwise only the remaining lines are checked, and the task is settled on completion.
03Run in the background
The task runs on its own — close the page if you like. A failure is reported straight away and fully refunded.
04Download the result
Collect the file from the bulk check page. You pay only for emailes that actually returned a result; the difference is refunded.
Result fields
Columns in the result file
The download is a single CSV file containing this full table.
Result file columns
identifier·alex.kim@example.com— The submitted email address, in lower case.activated·true— Whether the address can receive mail: true (reachable) or false (not reachable).
Best for
When to reach for this one
- List cleaning
- Database hygiene
- Periodic re-checks
Direct answer
What is the bulk Deliverability check?
Bulk deliverability check is built for lists from a thousand addresses upward: upload a file, the task runs in the background, and you download the result CSV when it completes. Any domain is accepted in the same file — there is no provider to choose.
Clear boundaries
Limits of this product
- It is not identity verification. A result says whether the address can receive mail; it cannot confirm who owns it.
- It never returns message history, conversation content, or any private account content.
- The avatar check covers the Gmail, Yandex and Mail.ru domains. Mix all three in one file freely; addresses outside that list fail the task with a count, refunded in full. The deliverability check accepts any domain.
- Results reflect the moment the task ran. Run it again for a fresh state — stored results are never refreshed for you.
- Download links expire. Fetch the file soon after the task finishes; if a link expires, check the task again for a new one.
When bulk fits
When bulk is worth it — and when realtime is faster
| Realtime check | Bulk check | |
|---|---|---|
| How many emailes | 1 email per single check; several per multi request — exact caps are in the API docs | A whole large list in one task — the current size range is on the pricing page |
| Getting results | Right away: single and multi-endpoint answer in the same response; the dashboard returns them one by one | Download a result file when the task finishes |
| Provider scope | No restriction — mix freely in one request | The full-address check takes any domain in one file; the avatar check accepts Gmail, Yandex and Mail.ru mixed in one file, and nothing outside those three |
| Result shape | JSON, fields per email | Result file (one CSV with the full table) |
| Typical use | Form validation, agent lookups, pre-send gating | List hygiene, pre-campaign filtering, stored-data cleanup |
Product FAQ
About Deliverability check
When should I use bulk instead of a realtime check?
Use bulk for a whole large list. For a handful of emailes the realtime check answers in the same request, with no task to schedule.
What happens to invalid emailes in the file?
The precheck drops malformed lines, so they never enter the billable count. Of the emailes that remain, any the upstream cannot resolve are not charged either. You pay only for emailes that actually return a result.
How long does a task take?
It depends on the email count and the product. You can close the page after submitting; the task runs in the background and the result waits for you on the bulk check page.
Do I get refunded if it fails?
Yes. A failed task is refunded in full. If the task succeeds but some emailes return nothing, that portion is refunded automatically. The difference between the reserved amount and what was actually charged always comes back.
Related products
Other bulk products
Create an account to submit a bulk task
Bulk and realtime checks draw on the same balance — nothing extra to enable. Sign up and upload your first file on the bulk check page.