Question 1

How does DQVerify check whether an email address is valid?

Accepted Answer

Every check runs three steps. First, an MX record lookup confirms the domain is set up to receive mail. Second, a live SMTP handshake asks the receiving mail server whether it accepts that specific mailbox. No message is ever sent, so the recipient never sees anything. Third, a reputation check compares the address against known disposable providers such as Mailinator, role-based prefixes such as admin@ and noreply@, and known spam trap addresses. The response combines these into a Low, Medium, or High risk score and a two-digit result code. Most checks return in well under a second, so you can run them live in a signup or checkout form, or in bulk on a CSV before a campaign.

Question 2

What do the email validation result codes mean?

Accepted Answer

Each response includes a code so your application can route the record automatically. 00 means the address is valid. 01 means the domain accepts mail but the mailbox could not be confirmed. 02 means the mailbox was not found on the domain. 03 means the inbox is full, and 04 means the input was empty. Codes in the 90s mean the address should not be mailed: 91 is a syntax error, 92 a non-existent domain, 93 a blacklisted domain, 94 a reserved or role-based name, 95 a disposable address, 96 a blocked IP, and 99 a domain that did not respond. A common pattern is to accept 00, flag 01 and 03 for review, and reject the rest at the point of entry.

Question 3

Will validating my list reduce bounces and protect my sender reputation?

Accepted Answer

Yes, that is the main reason teams validate before they send. Mailbox providers watch hard bounce rates and spam trap hits closely. A list with many dead or mistyped addresses can push you into the spam folder, even for subscribers who genuinely want your email. By removing addresses that fail the SMTP check (code 02), domains that do not exist (92), disposable inboxes (95), and known traps, you only send to mailboxes that accept mail. Validation does not guarantee inbox placement, which also depends on content, authentication (SPF, DKIM, DMARC), and engagement. It does remove the bounces and traps that most often damage a sending domain. Clean the list before each large campaign and validate new signups in real time.

Question 4

Can I validate emails in real time on a signup form?

Accepted Answer

Yes. Send a POST request with the address to the email endpoint (/api/external/validate/email), using your API key as a Bearer token. The JSON response returns the result code and risk score in under 150 ms at the 95th percentile. That is fast enough to show an inline message before the user submits, such as "This looks like a disposable address" or "Did you mean gmail.com?". The same API key works for the address and phone endpoints, so a checkout or registration form can check all three fields in parallel from one integration. Each check is a separate call and uses one credit from the pack for that check type. Code samples for curl, Node.js, and Python are on the developers page.

Question 5

Can I clean an existing email list without writing code?

Accepted Answer

Yes. Upload a CSV or spreadsheet in the DQVerify dashboard and map the email column with the drag-and-drop column mapper. No fixed file format is required. DQVerify runs the same MX, SMTP, and reputation checks as the API and returns an enriched file with a result code and risk score on every row. Files under 50,000 rows typically finish in under ten minutes. Larger files process in the background and notify you when they are ready. Download your results during your session, because batch output is deleted afterwards. Validation inputs are processed in real time and not retained. The 1,000 free credits you get at signup work for batch uploads too, so you can test a sample of your own list first. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026.

Question 6

How much does email validation cost?

Accepted Answer

Each email check costs one credit. Every account starts with 1,000 free credits and no credit card is required, so you can test the service on real data. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026. After that, credit packs start at $275 for 20,000 credits, with volume tiers up to 500,000. There is no monthly subscription and no auto-renewal. Paid credits are valid for one year from purchase. Email credits cover email checks. If you add address or phone validation later, you buy a pack for that check type and use the same API key. Email is one of the lower-cost modules because it does not rely on licensed postal or carrier data. The pricing page has a calculator that shows the exact cost for your volume.

Email validation that catches the bounce before you send.

Four checks between the form and the inbox.

Format

Domain

Mailbox

Risk

Check emails at signup and before every send.

What customers say.

Pay for what you verify.

Email validation questions

Clean your list before the next send.