Can email verification be used for cold outreach?

Verification tells you whether an address on a list you already hold can receive mail. It cannot find an address, guess one, or supply one, so it adds nobody to a list. Cleaning a purchased or scraped list does not create permission to mail it, and ListCheckup prohibits using the service on lists obtained without a lawful basis.

Does an email verification service send email to the addresses it checks?

It should not, and this one does not. The check opens an SMTP conversation with the mail server, asks whether the address would be accepted, and closes the connection before any message exists. Nobody on the list receives anything.

What lists is an email verification service meant for?

Lists the sender built themselves: subscribers who opted in, customers who bought something, people who handed over an address knowingly. Verification is hygiene on a permission-based list, not a way to acquire one.

Acceptable use

What ListCheckup is for, and what it will not help you do.

ListCheckup checks whether the addresses on a list can receive mail. It is a hygiene tool for a list you already have, and this page says plainly who that list has to belong to. Everything here also appears in section 4 of the Terms, which is the version that binds; this is the same policy in ordinary language.

What it is for

A list you built yourself. Subscribers who opted in, customers who bought something, people who handed you an address knowingly — and who, months or years later, may no longer be reachable at it. People change jobs and abandon mailboxes without editing anybody's list, which is the entire problem this solves.

The typical user is a shop owner with a few thousand subscribers collected over several years, about to send the first campaign in a long time, who would rather find out which addresses are dead before a mail provider finds out for them.

What it is not for

You may not use ListCheckup to:

check addresses you obtained without a lawful basis, including scraped, purchased, rented or otherwise acquired lists;
support the sending of unsolicited bulk email, or any activity that breaches anti-spam law in the recipient's jurisdiction;
test guessed or generated addresses to work out which ones exist, at your domain or anyone else's;
enumerate the mailboxes of an organisation you have no relationship with.

Cleaning a purchased list does not turn it into a list you are permitted to mail. The bounces go away and the legal position does not change.

What the service cannot do, by construction

These are not undertakings about how we intend to behave. They are properties of what the software is, and they are why the paragraph above is enforceable rather than decorative.

It supplies no addresses. ListCheckup holds no contact database, sells no data, and has nothing to look anybody up in. Every address it examines is one you already had. It cannot grow a list by a single row.
It never sends mail. A check opens a conversation with the receiving mail server, asks whether an address would be accepted, and hangs up before a message exists. Nobody on your list hears from us, and nothing arrives in anyone's inbox.
It finds and generates nothing. There is no address discovery, no pattern guessing from a person's name, and no way to ask it who works somewhere.

The result is a tool that makes an existing list smaller and more accurate. There is no configuration of it that reaches somebody who was not already on your list.

Sending responsibly

Verification is one part of sending well, and the smaller part. The rest is consent you can evidence, authentication on your domain, a working one-click unsubscribe, and paying attention to complaint rates — the requirements mail providers now publish openly. A clean list sent without permission still belongs in the spam folder, and it will reach it.

Enforcement

If we have reason to believe an account is being used against this page we may suspend it and refuse further verification. Unused credits on an account suspended for this reason are refunded under the Refund Policy; we would rather return the money than keep it for work we are not willing to do.

If you are not certain whether your list qualifies, ask before you upload it. Email [email protected] and describe how the addresses were collected. A plain answer costs us nothing and is better for both of us than a suspension afterwards.