Online email address verification results guide

Introduction

This short guide will help to understand our customers how to get maximum information from our email verification reports.
Bulk email verifier's result it's three CSV reports: "all","valid","detail".
example of email verification

Attention: not all text editors of Windows displaying file correct, pls use WordPad editor instead of default Notepad.
If all emails in report going in one row, or more than one email address per row - it's wrong editor and not issue of our service.

Understanding of "all" report

This type of report consist of email address and status. It's row structure is "email@email.com","status", this is file of example.
In text editor it will looking like this:

"user1@email.com","ok"
"user2@email.com","fail"
"user3@email.com","unknown"
"user4@email.com","ok"

Status "ok" will be if three conditions will be true:

email service answer us that ready to receive letter
no antispam tricks in use
email service do not answering that any email is valid

Status "fail" will be if five conditions will be true:

email service answer us that will not receive letter to this email
server is down
smpt server working incorrect
no antispam tricks in use
email syntax is incorrect

Status "unknown" will be if two conditions will be true:

looking like antispam tricks in use
email service answering "valid" for any email

We do not take money for "unknown" emails.

Understanding of "valid" report

This report - it's all emails from "all" report where status is "ok". Row structure is "email@email.com", looking like:

"user1@email.com"
"user4@email.com"

Understanding of "detail" report

This newest type of report, created for advanced customers. Row structure is "email@email.com","substatus", looking like:

"user1@email.com","ok"
"user2@email.com","p_unknown_email"
"user3@email.com","t_attempt_rejected"
"user4@email.com","dead_server"

There are 13 sub-statuses, prefix "t_" or "p_" can be added to sub-status, so sub-statues in report can be with/without prefix.
List and description of sub-statuses:

"ok" - all is ok, server saying that ready to receive letter to this address and no tricks detected
"error" - server saying that delivery failed, but no information about email existence or availability
"smtp_error" - answer of smtp server is invalid or server responding with some internal error
"smtp_protocol" - smtp server allow us to connect, but closing smtp session before email was verified
"unknown_email" - server saying that delivery failed and email not exist
"attempt_rejected" - delivery fail, reason similar to "rejected"
"relay_error" - delivery fail because of some relaying problem
"antispam_system" - some antispam technology blocking verification progress
"email_disabled" - email account is suspended/disabled/limited and can't receive emails
"domain_error" - email server or dns for whole domain is not installed or incorrect, so all emails are not deliverable
"ok_for_all" - email server saying that ready to accept letter to any email
"dead_server" - email server is dead, no connection to it
"syntax_error" - syntax error in email address
"unknown" - email delivery fail but no information about reasons
"email_exists" - email exists but we have no deliverability information (from 22 of June 2019, see more on verify yahoo email)

Prefix "t_" mean "temporary", "p_" mean "permanent". Prefix very useful because giving additional information about situation:
"p_email_disabled" - it means that server say that email is permanently disabled
"t_attempt_rejected" - it can happens when server just overloaded, and temporary reject verification
"p_error" - no information about email existing, but no chance to deliver email in future too
"t_error" - no information about email existing, but there is some chance that email is alive.
Sub-statuses with prefixes very powerful tool for email results understanding and choosing emails for mailing.

Interesting facts for deeper understanding

There is only one method to be 100% sure that email address is really exist - send email letter.
There are no software or online tools in the world that can verify any email address 100% correct.
Why? Because it's theoretically impossible in case of some email services.
See example of unverifiable email service on scheme.
example of smtp that hard to verify

There is only one email verification method, it's called "SMTP verification", and it's based on data analysis in connection1.
So how "SMTP verification" can know that destination emails server will send bounce in second connection?
There are lots email servers that not compatible with smtp standards, so biggest part of software and online verification tools
giving fake results for it. Our service become one of the best verifiers because our verification based not only on standards,
it's based on large amount of experience.

Verify email list in two easy steps!