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Deliverability

How to Verify Business Email Addresses Without Paying Per Lookup

October 2026 · 6 min read

Bad addresses bounce, bounces hurt your sender reputation, and a damaged reputation sends good emails to spam. Here's what you can check for free before you hit send — and the limits worth knowing.

The short answer

You can catch a large share of bad business email addresses for free by checking three things before you send: the address is well-formed, the domain has mail servers (an MX record, or failing that an A record), and the address hasn't already bounced. That won't prove a specific mailbox exists — only an actual send can do that — but it removes typos and dead domains, which are the cheapest bounces to avoid.

Why bounces matter more than you'd think

Every email you send from your own domain builds a reputation with mailbox providers. Hard bounces — messages to addresses that don't exist — are a signal that you're sending to a list you haven't taken care of. Send enough of them and your legitimate emails start landing in spam, including the ones to people who would have replied.

For a seller working a list of a few dozen or a few hundred prospects a week from their own mailbox, a clean list matters more than volume. One careless import of a few hundred stale addresses can do more damage than a month of careful outreach can repair.

What a free check can tell you

What a free check can't tell you

Be honest about the limits, because overpromising here is how people get burned.

• It can't confirm a specific mailbox exists. jane@realcompany.com passes the check even if Jane left two years ago. Only the receiving mail server knows, and many won't say.
• Catch-all domains look valid for everything. Some companies accept mail to any address and sort it later, so a made-up name will pass.
• A network problem isn't proof of a bad address. If the lookup times out, the right answer is “unknown,” not “invalid.” A good checker never marks a real contact as dead because your Wi-Fi hiccuped.

Paid verification services go a step further by probing the receiving server, which can catch more dead mailboxes — at a cost per lookup, and with results that are still not guaranteed. For a seller sending tens of emails a day, the free checks plus careful bounce handling cover most of the practical risk.

How to check an MX record yourself

You don't need special software. On a Mac or a Windows PC, open a terminal or command prompt and run:

nslookup -type=mx example.com

If you see one or more mail servers listed, the domain can receive email. If you get “non-existent domain” or no mail records at all, drop the address. Good for spot-checking one prospect; tedious for a list of two hundred.

A simple pre-send routine

1. Clean the list on import. Check syntax and domains as addresses come in, not the night before a big send.
2. Re-check right before sending to anyone whose address is old or was typed by hand.
3. Send in measured batches rather than a few hundred in one go, especially from a new mailbox or domain.
4. Scan for bounces and replies after each send, and mark the bad addresses so the cadence stops.
5. Set up SPF, DKIM and DMARC on your sending domain — most hosts do this by default, but confirm it.

How The Drip handles it

The Drip runs the free checks for you. When you add or import a contact, it checks the address syntax and looks up the domain's MX record (falling back to an A record, then to your computer's own resolver if a network blocks the direct query). If the lookup fails because of a connection problem, the contact is marked “unknown,” never “invalid.” Contacts with a dead domain get an Invalid Email badge, and the send confirmation warns you before you email one — a warning rather than a hard block, because you keep the final say.

On the Schedule page, the Verify Emails button re-checks whichever queue rows you've highlighted right before you send, or backfills any contact that has never been checked if nothing's selected. And once you've sent, the bounce and reply checks flag addresses that came back undeliverable. No per-lookup fees and no list uploaded to a third-party service — the checks run on your own machine.

Frequently asked questions