MailFloo talks to each mailbox's own server, tells catch-all domains from real ones, and gets sharper with every message you actually send.
An address only reaches the live conversation once the quick checks have cleared it, so server contact is spent where it counts.
The address is parsed against the mail standard before anything leaves our server.
The domain has to resolve and publish mail servers, or the address stops right here.
Throwaway providers, parked domains and honeypot-shaped addresses are caught before any server is contacted.
Shared boxes such as info@ and free-mail providers are flagged so you can decide on them separately.
A live conversation with the receiving server asks whether that mailbox exists. No email is sent.
Accept-all domains get two invented probes, then the reply wording, the naming pattern and your delivery history are weighed into a score.
Each address carries its group, a 0 to 100 score and the reason behind it, so you can decide what goes into the send and what stays out.
The mailbox was confirmed by its own server, or a real message to it delivered.
No such mailbox, a domain that cannot receive mail, or a real message that hard-bounced.
The server accepts everything, so the clues are weighed into a likelihood instead of a shrug.
A possible spam trap, a server that kept deferring, or a domain with a poor delivery record.
Bring the file you already have and take back the same file with the verdicts added beside your columns.
Drop in a CSV or Excel file, or type a few addresses. Your columns come back exactly as they went in.
Format, domain, mail servers, then a live conversation with the mailbox's own server. Only worthwhile addresses reach that stage.
Take valid to the send, hold catch-all for a careful first pass, keep invalid out of the database.
A dead address looks like a good one until it bounces. Tell MailFloo what delivered and what bounced, and the next check on that company starts from what it already knows.
Record deliveries and bounces from your campaigns. Verdicts update within minutes.
An address you record as delivered becomes valid, even on a catch-all domain. One you record as hard-bounced becomes invalid, even if the server was polite.
A domain that accepts mail and then bounces it is treated with care next time. One that always delivers earns more trust.
A 0 to 100 score that is calibrated against real deliveries, so a 90 keeps meaning what a 90 should.
Plain answers to what people ask before they upload a list.
No. MailFloo communicates with the recipient's mail server to ask whether the address would be accepted, without transmitting an email message. Nothing reaches the inbox and nobody is contacted.
A company set up to accept mail for any address, real or not. The server never says no, so a plain check cannot tell a live mailbox from a typo. Many large companies work this way, which is why MailFloo adds a likelihood instead of just a label.
Valid: confirmed by its own server. Catch-all: the domain accepts everything, and the score says how likely this one is. Invalid: rejected, badly formed, disposable, or a real message to it hard-bounced. Risky or unknown: the server would not give a usable answer even after retries, or the address looks like a trap.
Because you tell it what really happened. A recorded delivery makes an address valid even on a catch-all domain; a recorded hard bounce makes it invalid even if the server accepts it. Temporary failures are never counted. The engine learns from both.
Yes. Every column you uploaded is kept, and the verdict, score and reason are added beside them. Download as Excel or CSV, in full or filtered.
Uploaded files and results are deleted after 30 days. What the engine keeps for learning is anonymised: the address is replaced by an irreversible fingerprint.
Sign in, upload a file or type a few addresses, and download the answers when the engine is done.