Result Codes and Terminology


By rachid idrissi

updated 14 days ago


A deliverable result means the recipient's email is valid. Email List Validation® determined this address is safe to send to within our 98% Deliverability Guarantee.



An invalid email means the email address does not exist, for one of the reasons you get in the validation report (please check next section: Detailed result guide).


Accept All

Emails that always returns a valid status, but from some domains that accept all emails, you attempt to send to them. Typically, these domains are trying to protect their legitimate users by telling the sending mail server it will accept the mail for a given email address, but then silently discard the message or send a bounce message after the fact.



Disposable addresses are created to be Valid only temporarily so their owners can sign up for promotions or services without using a primary address. Disposable addresses will not perform and typically just take up space in your database.



Email List Validation®  will return an unknown result when it was unable to get a response from the recipient's mail server. This often happens if the destination mail server is too slow or temporarily unavailable. In some cases, retrying your request after about 5 minutes will return a valid or invalid response. Unknown addresses don't count against your verification balance.



Spamtraps addresses are created not for communication, but rather to lure spam. In order to prevent legitimate email from being invited, the e-mail address will typically only be published in a location hidden from view such that an automated e-mail address harvester (used by spammers).


Understand the result codes within your report

Email List Validation ® first scans to identify disposable, spam-trap, and complaint emails and then runs the email identification process.

After your file has been verified, each email address in the list will be labelled with one of the following statuses:

  • Ok: All is OK. The server is saying that it is ready to receive a letter to, this address, and no tricks have been detected.

  • Error: The server is saying that delivery failed, but no information about, the email exists.

  • Smtp_error: The SMTP answer from the server is invalid or the destination server, reported an internal error to us.

  • Smtp_protocol: The destination server allowed us to connect but the SMTP, session was closed before the email was verified.

  • Unknown_email: The server said that the delivery failed and that the email address does not exist.

  • Attempt_rejected: The delivery failed; the reason is similar to “rejected”.

  • Relay_error: The delivery failed because a relaying problem took place.

  • Antispam_system: Some anti-spam technology is blocking the, verification progress.

  • Email_disabled: The email account is suspended, disabled, or limited and can not, receive emails.

  • Domain_error: The email server for the whole domain is not installed or is, incorrect, so no emails are deliverable.

  • Ok_for_all: The email server is saying that it is ready to accept letters,to any email address.

  • Dead_server: The email server is dead, and no connection to it could be established.

  • Syntax_error: There is a syntax error in the email address.

  • Unknown: The email delivery failed, but no reason was given.

  • Accept_all: The server is set to accept all emails at a specific domain. These domains accept any email you send to them.

  • Disposable: The email is a temporary address to receive letters and expires, after a certain time period.

  • Spam_traps: The email address is maintained by an ISP or a third party, which neither clicks nor opens emails.

  • Invalid vendor: The response is not recognized by our server. The SMTP server sent us a response which is not recognized by our server.

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