How to Verify an Email List: Upload, Read, Act

To verify an email list, export it as a CSV, upload it on the verify page, and download the results: every address comes back valid, risky or invalid, with a reason and a send-advice column. Send to the valid rows, test a small batch of the risky ones, and drop the invalid ones. Your first 100 checks are free with a Google sign-in, no card, so you can run your first 100 checks free on a slice of your list before paying for the rest.

The whole thing is usually a few minutes of your time plus waiting for the list to run. Here is the order that works.

Step 1: Get the list into a CSV

Export from your CRM, sequencer or spreadsheet as a CSV with one header row and your email addresses in one column. Keep your other columns (name, company, source); they are passed through to the results. If the file is an Excel workbook, use Save As, CSV. Very large lists are covered in what 50k to 100k emails cost and how long they take, and a file too big for Excel in verifying a list too big for Excel.

Before you upload, a free tidy-up saves checks: the email list cleaner and the CSV email verifier flag bad syntax, duplicates, typo domains and disposable addresses in your browser.

Step 2: Upload it on the verify page

Open the verify page, sign in with Google and drop the file in. The first 100 checks are free. If you want to see how your list splits before paying, upload a random slice first, not the top rows; the top of an export is often the newest and cleanest part.

Step 3: Wait for the finish estimate

Lists run on capacity shared by every customer, so each list card shows its own estimated finish time. Small lists come back fast. A big list takes longer, and the list keeps running if you close the tab. Rows that never reach a verdict (the server was unavailable, refused or deferred our check) do not spend free checks or credit packs.

Step 4: Read the three statuses

Status	What it means	Send advice
valid	The mail server confirmed the mailbox exists	safe
risky	The domain takes mail but the mailbox could not be confirmed (catch-all, role address, provider hides mailbox status, server would not confirm)	care or retry
invalid	It will bounce: bad format, no mail server, typo or disposable domain, or the mailbox does not exist	do_not_send

The results file keeps your original columns and adds status, reason and send_advice. The full explanation of every reason is in how to read a verification report.

Step 5: Act on each status

1. Valid: send. These are the rows the mail server confirmed. Download only the safe-to-send rows if you want a ready-to-import file.
2. Risky: test, do not blast. Group by reason. Catch-all domains accept every address, so no mailbox there can be confirmed; see what to do with catch-all emails. Send 100 to 300 from a warmed inbox, watch the bounce rate, and only then send more. Rows marked retry can be checked again later.
3. Invalid: suppress. Add them to your suppression list so they are not re-imported from another export.

Step 6: Download before the files expire

Result files and job records are deleted 7 days after a list is submitted. On paid plans, a finished list's risky addresses are kept for 14 days after it finishes so you can re-check them. Download the results and store each address's status and the check date in your CRM.

Step 7: Re-check before big sends

A verified address can go bad later. If weeks pass between verification and sending, re-check the older rows. A sensible habit is to re-check anything verified more than about a month before the send.

What verification does not do

It confirms a mailbox exists; it does not tell you whether the person wants your email, whether it lands in the inbox rather than spam, or whether you have permission to send. Outlook, Hotmail, Live and MSN addresses currently come back risky, because Microsoft refuses mailbox checks from our server's network, and Yahoo addresses are hard to confirm; see checking a list of Outlook and Hotmail addresses and checking Yahoo and AOL addresses. More on cleaning in general: how to clean an email list.

What it costs

After the 100 free checks: Starter is $9 a month for 2,500 emails, one-time packs start at $15 for 10,000 checks and never expire, and Pro is $39 a month with the first 100,000 checks a month at full speed, then slower, never cut off. See pricing.

Verify your list now

Upload your list on the verify page: 100 free checks, Google sign-in, no card.