> ## Documentation Index > Fetch the complete documentation index at: https://docs.revenuebase.ai/llms.txt > Use this file to discover all available pages before exploring further. # Use Email Verifier > Verify a single email or a CSV/JSON list, understand the results, and download your completed batch. Open **Email Verifier** in the [RevenueBase portal](https://app.revenuebase.ai) to check whether an address is deliverable. You can check one address or upload a list. ## Credits and plans | Result or action | Pay-as-you-go (PAYG) | All-you-can-eat (AYCE / Unlimited) | | - | - | - | | **Valid** result | **1 credit** | **1 credit** | | **Invalid** result | **1 credit** | **1 credit** | | **Unknown** result | **Free**, 0 credits | **Free**, 0 credits | | Upload, check progress, cancel, or download | **Free**, no additional charge | **Free**, no additional charge | | Request metadata through the API | **Included**, no extra cost | **Included**, no extra cost | Unlimited contact retrieval does not include unlimited email verification. Verification uses the same per-result prices on both plans. Before a batch starts, you need enough available credits for its email count at one credit each. The final charge counts **Valid + Invalid** results. For example, 1,000 inputs with 800 Valid, 150 Invalid, and 50 Unknown results cost **950 credits**. ## Verify one address 1. Open **Email Verifier**. 2. Enter the address under **Verify a single email address**. 3. Click **Verify email**. 4. Read the status beside the address. | Status | Meaning | What to do next | | - | - | - | | **Valid** | The address was confirmed as deliverable at the time of the check. | Use it in your outreach workflow, subject to your usual sending practices. | | **Invalid** | The verification determined that the address is not deliverable. | Remove or correct it before sending. | | **Unknown** | The check could not establish a conclusive result. | Keep it separate from confirmed Valid results; consider checking it again later. | An Unknown result does not confirm that the address is invalid. A Valid result describes the check at that time; it does not guarantee inbox placement for every message. ## Verify a list ### Prepare your file Upload a **CSV or JSON file up to 25 MB** with a field named **`email`**. Optional columns are preserved in the output, so you can keep an internal contact ID beside each address. For example, a CSV can contain: ```csv theme={null} email,contact_id alex@example.com,contact-001 jamie@example.com,contact-002 ``` Use the template offered in the upload area if you need a starting file. Rows without an email are skipped. ### Submit the batch 1. Drag the file into **Upload email list**, or choose it from your computer. 2. Review the detected email count, skipped rows, and credit estimate. 3. Confirm that you have enough available credits, then start verification. 4. Find the batch in **Job history** below the upload area. If you do not have enough credits, an admin can add organization credits or adjust your monthly limit. You can also submit a smaller list. See [Organization settings](https://docs.revenuebase.ai/docs/portal/organization-settings.md#understand-shared-credits-and-monthly-limits). Watch: Verify a list before you send ## Track progress and download results Use the status filter in **Job history** to find a batch. Completed jobs show their row counts, Valid, Invalid, and Unknown totals, and credits used. | Job status | What it means | Available next step | | - | - | - | | **Queued** | Waiting to begin. | Wait, or cancel the batch. | | **Processing** | Verification is running. | Wait, or request cancellation. | | **Complete** | Processing has finished. | Download from the file name or download icon. | | **Error** | The job ended with an error. | Read the error message before deciding whether to submit again. | | **Cancelling** | A cancellation request is being processed. | Wait for the final state. | | **Cancelled** | The batch stopped before completion. | Download any available partial output. | To cancel a queued or processing batch, choose its cancel control and confirm. Checks already processed as Valid or Invalid remain billable. Cancellation does not refund those checks. Downloading the same completed batch again adds no verification charge. Submitting the file as a new batch runs new checks and can charge again. ## Understand metadata and email providers The portal shows the main **Valid**, **Invalid**, or **Unknown** result. If your workflow needs detailed metadata, use the [Email Verification API](https://docs.revenuebase.ai/api-reference/v2/email-verification-overview.md) and request metadata there. **Requesting metadata does not increase the cost.** The [metadata reference](https://docs.revenuebase.ai/api-reference/v2/email-verification-metadata.md) explains the detailed statuses, catch-all results, and email-provider classifications. A provider value of Unknown is separate from a verification result of Unknown. For high-volume outbound workflows with tools such as Smartlead or Instantly, `email_provider` can help you group Google and Microsoft recipients for provider-matched sending. Customers have reported benefits from this approach, but RevenueBase has no controlled benchmark for the size of the improvement. See the [provider guidance](https://docs.revenuebase.ai/api-reference/v2/email-verification-metadata.md#metadata-fields). To find or add information about people and companies, use [Audience Builder](https://docs.revenuebase.ai/docs/portal/audience-builder.md#match-a-list-you-already-have). This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.