Page tree
Skip to end of metadata
Go to start of metadata


Warning Codes


The table contains a list of current and upcoming warning types that the service can report on when processing an email address. These codes and notes will appear in the WarningCodes and WarningDescriptions fields.

Important Note!
New codes and descriptions will be added to the table as new features become available.


CodeWarningDescription
0UnrecognizedTLDIndicates if the top-level-domain is not recognized by ICANN.
1InvalidSyntaxIndicates if the email is syntactically invalid.
2InvalidDomainSpecificSyntaxIndicates if email is syntactically invalid for the given domain.
3InvalidDNS

Indicates if the domain is unregistered or it does not have at least one MX or A record configured to relay email.

4NoMXRecordsIndicates that the registered DNS does not have an MX record.
5Established

Indicates that the email address is known to be in bulk marketing lists.

6Alias

Indicates if the email address is believed to be an alias address.

7Bogus

Indicates if the email address is believed to be a bogus email. For example, asdf@asdf.com.

8BogusSMSAddress

Indicates if the email address is believed to be a bogus SMS domain address.

9Garbage

Indicates if the email address is believed to contain garbage-like keyboard strokes and/or garbage-like characters.

10

Vulgar [1]

Indicates if vulgar words or content are found in the email address.

11MailBoxIsFull

Indicates if the mailbox is currently full and unable to receive any new messages.

12MailboxIsBusy

Indicates if the mailbox is reported by the hosting mail server as being busy and unable to currently accept new messages.

13

DisposableEmail [2]

Indicates if the email address is believed to be disposable. Disposable email address are generally only valid for a short period of time before they are disposed and are then no longer valid.
14SpamTrap

Indicates if the mailbox is believed to be a spam trap.

15KnownSpammer

Indicates if the email address is known to have participated in spam-like activities.

16

BlacklistedDomain [3]

Indicates if the domain was found to be in one or more blacklists.

17KnownComplainer

Indicates if the email address has been identified as a known complainer of receiving unsolicited mail. ** Coming Soon **

18KnownGreylisterIndicates if the mail server is known to commonly use greylisting techniques. This means that if your mail server is communicating with this domain for the first time or if you are sending bulk messages or messages in high frequency then you may be greylisted by them and experience temporary bounce backs.
19OptInRequiredIndicates if the mail server requires opting-in to send and receive messages.
20

IsWhiteListOnly [3]

Indicates if the mail server only relays messages for users that are whitelisted.
21ConnectionRefusedIndicates if the mail server refuses to accept an SMTP connection.
22Email is Bad - Subsequent checks halted.Indicates that the email address failed a critical check, such as SMTP verification.
23BotIndicates that the email address has been reported as being a known bot.

Note Codes


The table contains a list of current and upcoming note types that the service can report on when processing an email address. These values will appear in the NotesCodes and NotesDescription fields.

Important Note!
New codes and descriptions will be added to the table as new features become available.


CodeNoteDescription
0CCTLDIndicates if the top-level-domain (tld) represents a specific country. For example ".us" implies United States.
1FreeIndicates if the domain of the email is a public-register domain, where users can sign up for email accounts for free.
2SMSDomain

Indicates if the domain is a known Mail-to-SMS Gateway.

3RoleIndicates if the email address appears to be a role that is designed to be anonymously managed by one or more persons.
4BusinessAddress

Indicates if the email address appears to be work related.

5

GreyListed [3]

Indicates if the mail server responded with a known greylist tactic.
6MailServerTemporarilyUnavailable

Indicates that the mail server may be temporarily unavailable or too busy to respond.

7ServerConnectTimeoutIndicates that a connection to the recipient mail server could not be established.
8MailBoxTimeoutIndicates that the connection to the mail server timed out when trying to verify the email address.
9

TemporaryReject [4]

Indicates that the email address was temporarily rejected by the mail server. This is also known as a soft-bounce and the rejection is not permanent. There are many reasons for why a mail server may respond with a temporary reject. The mailbox or server may be busy, unavailable, or using a greylist. When a mail server does this it typically wants you to wait at least 15 minutes and then try again later.

10SlowMailServerIndicates that the host mail server is known to communicate slowly and that real-time verification of an email address may not be possible unless adequate time is provided. In some cases a timeout time of 90 seconds or more may be necessary to verify email addresses with these mail servers.
11

Varies

Example: JP

***Coming Soon: Countries: The ISO2 country code for the country where the mail server(s) is located. If mail servers are found in more than one country, then all country ISO2 codes will be represented in a pipe-delimited list.
12

Varies

Example: OS|TY

***Coming Soon: Region: The region in the country where the mail server(s) is located. The region is commonly returned as a two-character abbreviation. If mail servers are found in more than one region then the value will be a pipe-delimited list of the regions.
13

Varies

Example: Osaka|Tokyo

***Coming Soon: Localities: The name of the locality where the mail sever(s) is located in. If mail servers are found in more than one locality then the value will be a pipe-delimited list of all the localities.

14

Varies

Example: 543-0062|102-0082

***Coming Soon: PostCodes: The post code of where the mail server(s) is located. If multiple post codes are found, then the value will be a pipe-delimited list.
15SMTPCheckTimeoutIndicates that SMTP communication did not finish in the allotted time. It is recommend to increase the timeout time and try again.
16TLSIndicates that the recipient mail server supports Transport Layer Security (TLS) connections for encrypted email communication.


References

  1. ^ Improved Vulgar Word Detection in Email Validation Service

  2. ^ Identifying Disposable Email Addresses: A Better Approach

  3. ^ 1 2 3 3 Email Validation Terms You Should Know

  4. ^ Tackling False Negatives in Email Validation


  • No labels