Email verification for Clay and GTM engineering agencies
GTM engineering agencies build enrichment tables for clients and hand the rows to a sequencer. A waterfall can return an address nobody has confirmed exists, so add a verification column before the export. One HTTP API column calls SimpleVerifier on each row and returns an action (send, send_with_care, retry_later or do_not_send). Agency ($249 a month) includes 300,000 API calls a month, 15 seats and client workspaces.
Plan details as of 23 Oct 2026. The pricing page is the source of truth.
The use case
You run a Clay table per client: a list of accounts, people found at each, an email from one or more enrichment providers, then an export to Instantly, Smartlead or a CRM. Each row's email is a guess until a mail server confirms it. A verification column at the end of the table filters on the result, so only confirmed mailboxes leave the table and catch-alls go to a smaller campaign.
The workflow
- 1
Create an API key
Make a key in the dashboard. Teammates on a seat share the account's keys and volume, so one key can serve the agency's tables.
- 2
Add one HTTP API column
In the client's Clay table, add an HTTP API column that calls the verify endpoint with the row's email and your key as a Bearer header. The Clay integration page has the exact request.
- 3
Filter on action
Keep rows where action is send for the main campaign. Send_with_care rows (catch-alls and other unconfirmed addresses) go to a smaller, slower campaign or get dropped.
- 4
Mind the rate limit
Each key allows up to 120 calls a minute. Set Clay's rate limit below that, and keep auto-run off until you have checked a few rows.
- 5
Bulk files go through upload
For a big one-off client list, upload the CSV to the dashboard instead of running it row by row. On Agency, file it under the client's workspace.
Which plan fits
Count API calls first: each Clay row you verify uses one. Business ($99) includes 100,000 calls a month and 5 seats; Agency ($249) includes 300,000, 15 seats and client workspaces for uploaded lists. Past the included calls, monthly billing adds $1.00 per 1,000.
Full speed is a monthly volume, not a promise of hours. Mailbox checks are paced and the day's check capacity is shared between customers, so a very large list takes days. It queues rather than failing, and the job card shows an estimated finish time. Plan client deadlines around that.
API calls are not unlimited: every plan includes a monthly number, then they are billed per 1,000 on monthly billing. Verification also does not check consent; follow the sending rules for each client and region.
What does your client book cost to verify each month?
Enter how many clients you run lists for and the size of a typical list each month. The starting numbers are only a starting point. Nothing is sent anywhere.
100,000 addresses a month. Cheapest SimpleVerifier plan that covers it at full speed: Pro, $39 a month. No seats or client workspaces on Pro.
| Verifier | Cheapest published route, per month | Source |
|---|---|---|
| SimpleVerifier Pro | $39 (flat, not per email) | Our pricing |
| DeBounce | $124 ($124.20/mo plan with 100,000 a month) | Pricing pageread 2026-11-02 |
| MillionVerifier | $149 (Pay as you go: 100,000-credit pack at $1.49 per 1,000) | Pricing pageread 2026-11-02 |
| NeverBounce | $159 ($159/mo plan with 100,000 a month) | Pricing pageread 2026-11-02 |
| Bouncer | $320 ($320/mo plan with 100,000 a month) | Pricing pageread 2026-11-02 |
| Emailable | $357 ($357/mo plan with 100,000 a month) | Pricing pageread 2026-10-30 |
| Clearout | $360 ($360/mo plan with 100,000 a month) | Pricing pageread 2026-11-03 |
| ZeroBounce | $449 ($449/mo plan with 100,000 a month) | Pricing pageread 2026-10-30 |
Competitor figures are the cheapest published route that covers the volume in one month: a subscription tier whose allowance covers it, or the pay-as-you-go pack bought again each month. They price verification credits only; we have not compared their team features. Prices change, so check each page before you decide. Full speed is a monthly volume, not a promise of hours. Mailbox checks are paced and the day's check capacity is shared between customers, so a very large list takes days. It queues rather than failing, and the job card shows an estimated finish time. Plan client deadlines around that.
Start with your own list
Sign in with Google and check your first 100 addresses free, no card, then download the results. When you are ready, Business is $99 a month and Agency is $249 a month, monthly billing, cancel anytime.
A walkthrough is a conversation by email with the support team. See also contact.
Common questions
- Is there a native SimpleVerifier provider in Clay?
- Not yet. You connect it with Clay's HTTP API column and a Bearer key. The recipe is on the Clay integration page.
- Are catch-all emails returned as send?
- No. A catch-all address is status risky with action send_with_care, never valid, because the server accepts every address and an SMTP check cannot confirm the mailbox.
- How do seats and client workspaces work?
- A seat is one person, the owner included: Business has 5 seats and Agency has 15. Teammates share the account's lists, monthly volume and API keys. Client workspaces are on Agency: you pick a client when you upload a list, then filter History and exports by client. Deleting a workspace keeps its lists; they just lose the label.
- Can we call it from our own tooling?
- Yes. Business includes 100,000 API calls a month and Agency 300,000, then $1.00 per 1,000 on monthly billing. Docs are at /docs/api.
Related
Other kinds of agency
- Cold email agencies
- Lead generation agencies
- SDR and outsourced sales teams
- Recruiters and staffing agencies
- Marketing agencies managing client lists
- Deliverability consultants
- Data and list brokers
- Appointment setting agencies
- Email marketing agencies
- Staffing agencies doing business development
- B2B data providers and enrichment vendors