no_connect
No mail server accepted a connection on port 25
The MX hosts resolved but none of them accepted a connection: a firewall, a server that is down, or an MX that points at something other than a mail server.
- appears in
- smtp_reason
- credits
- Free: an answer the mailbox check could not settle costs nothing and leaves no 7-day repeat marker; the settling re-checks bill 1 credit only when they confirm the mailbox. A verdict another signal decides, such as role, bills 1 credit as that verdict.
What it means
Different from mx_unresolvable, where the hosts do not even resolve. Here DNS is fine and the machines refuse or drop the connection. The mailbox stays unverified and the free signals decide the verdict.
What to do
Retry later. If no_connect persists for days on a business domain, its mail is probably broken and the addresses should be treated as risky.
Example response
{
"deliverable": "risky",
"reason": "unverified",
"smtp_checked": false,
"smtp_reason": "no_connect",
"mailbox_exists": null
}Abbreviated: a real answer carries all 46 fields, listed in the verify-email reference.
Related
- no_mailbox · the server answered that the mailbox does not exist
- disabled · the server reported the mailbox as disabled or suspended
- greylisted · the server deferred the handshake and asked the sender to come back later
- timeout · the mail server did not answer within the probe's time limit
- mx_unreachable · the mail exchangers could not be reached from the verification network
- delivered_recently · your own delivery report confirmed this mailbox
- provider_unavailable · the verification provider itself could not answer
- All verdict reasons
- Verdicts and the risk score
- API reference
markdown version: /docs/reasons/no_connect.md