Email validation

Introduction

This Email Validation API is a lightweight yet powerful tool designed to verify and clean email addresses from your data sources. By analyzing the structure, domain, SMTP records, and other key indicators, the API determines whether an email is real, active, and safe to use. The output provides all the necessary technical and deliverability insights required to ensure your contact list is accurate and up-to-date.

Use Case:

1. Database Cleaning & Hygiene

This API is ideal for bulk email verification to clean outdated or fake addresses from CRMs, subscriber lists, or marketing databases. By identifying invalid or risky email addresses, businesses can:

Improve deliverability rates
Avoid blacklisting from mail service providers
Reduce bounce rates and spam flags
Enhance sender reputation and campaign performance

2. Pre-Submission Email Checks

Integrate this API into signup or contact forms to instantly validate emails at the point of entry. This ensures:

No fake or mistyped emails enter your system
Improved user onboarding quality
Lower risk of spam or abuse

3. Risk Assessment in Fintech or Regulated Environments

For industries like fintech, regtech, and digital onboarding, email verification is a key step in identity validation and fraud prevention. Identifying disposable or recently registered domains can help flag suspicious users early in the funnel.

API details

Endpoint

POST https://api.signzy.app/api/v3/validation/email

POST https://api-preproduction.signzy.app/api/v3/validation/email

Request body parameters

Parameter	Data Type	Description	Required
emailId	String	The email address to be validated.	Mandatory

{
    "emailId": "<Email id>"
}

Request Headers

Name	Value	Required	Description
Content-type	application/json	Mandatory	The type of content that the request body contains.
Authorization	XXXXXXXXXXXXXXX	Mandatory	An authentication token to authorize the request. Reach out to the Signzy support team to get one created.

Code Samples

curl --location 'https://api.signzy.app/api/v3/validation/email' \
--header 'Authorization: <Authorization token>' \
--header 'Content-Type: application/json' \
--data '{
    "emailId": "<Email ID>"
}'

Response body parameters

Parameter	Data type	Description
emailId	String	The email address being verified
ip	String	[Deprecated] Will be removed in future versions.
id	Integer	Unique identifier for the verification process
result	Object	The result of the email verification process
result.emailverifyData	Object	Data related to the email verification result
result.emailverifyData.email	String	The email address being verified
result.emailverifyData.status	String	Whether the email is valid or not. The possible values are "valid \| invalid \| catch-all \| unknown \| spamtrap \| abuse \| do_not_mail". The descriptions are mentioned below in the table.
result.emailverifyData.sub_status	String	Possible Values are "antispam_system \| greylisted \| mail_server_temporary_error \| forcible_disconnect \| mail_server_did_not_respond \| timeout_exceeded \| failed_smtp_connection \| mailbox_quota_exceeded \| exception_occurred \|possible_traps \| role_based \|global_suppression \| mailbox_not_found \|no_dns_entries \| failed_syntax_check \|possible_typo \| unroutable_ip_address \| leading_period_removed \| does_not_accept_mail \| alias_address \| role_based_catch_all \| disposable \| toxic". The descriptions are mentioned below in the table.
result.emailverifyData.free_email	Boolean	Indicates if the email is from a free email provider
result.emailverifyData.did_you_mean	String	Suggested correction for the email address
result.emailverifyData.account	String	The account name of the email ID holder
result.emailverifyData.domain	String	The domain of the email address
result.emailverifyData.domain_age_days	String	Age of the email domain in days.
result.emailverifyData.smtp_provider	String	The SMTP provider associated with the email
result.emailverifyData.mx_found	Boolean	Indicates if MX records were found for the domain
result.emailverifyData.mx_record	String	The MX record associated with the email domain
result.emailverifyData.gender	String	Gender associated with the email address.
result.emailverifyData.country	String	The country associated with the email address
result.emailverifyData.region	String	The region associated with the email address
result.emailverifyData.city	String	The city associated with the email address
result.emailverifyData.zipcode	String	Zip code associated with the email address
result.emailverifyData.firstname	String	First name associated with the email address
result.emailverifyData.lastname	String	Last name associated with the email address
result.emailverifyData.name	String	Full name associated with the email address

{
    "emailId": "<Email ID>",
    "ip": "",
    "id": <Unique ID>,
    "result": {
        "emailverifyData": {
            "email": "<Email ID>",
            "status": "valid/Invalid",
            "sub_status": "",
            "free_email": "true/false",
            "did_you_mean": "",
            "account": "<Account name of the email ID holder>",
            "domain": "<Domain>",
            "domain_age_days": "3134",
            "smtp_provider": "g-suite",
            "mx_found": "true",
            "mx_record": "aspmx.l.google.com",
            "gender": "<Gender>",
            "country": "<Country>",
            "region": "<Region>",
            "city": "<City>",
            "zipcode": "<Zip code>",
            "firstname": "<First name>",
            "lastname": "<Last name>",
            "name": "<Name>"
        }
    }
}

Status Code

DELIVERABILITY STATUS EXPLANATION

valid- These are emails that we determined to be valid and safe to email to, they will have a very low bounce rate of under 2%. If you receive bounces it can be because your IP might be blacklisted where our IP was not. Sometimes the email accounts exist, but they are only accepting mail from people in their contact lists. Sometimes you will get throttle on number of emails you can send to a specific domain per hour. It's important to look at the SMTP Bounce codes to determine why.
invalid- These are emails that we determined to be invalid, please delete them from your mailing list.
catch-all - These emails are impossible to validate without sending a real email and waiting for a bounce. The term Catch-all means that the email server tells you that the email is valid, whether it's valid or invalid. If you want to email these addresses, I suggest you segment them into a catch-all group and know that some of these will most likely bounce.
spamtrap- These emails are believed to be spamtraps and should not be mailed. We have technology in place to determine if certain emails should be classified as spamtrap. We don't know all the spamtrap email addresses, but we do know a lot of them.
abuse- These emails are of people who are known to click the abuse links in emails, hence abusers or complainers. We recommend not emailing these addresses.
do_not_mail- These emails are of companies, role-based, or people you just want to avoid emailing to. They are broken down into 6 sub-categories "disposable","toxic", "role_based", "role_based_catch_all", "global_suppression" and "possible_trap". Examine this file and determine if you want to email these address. They are valid email addresses, but shouldn't be mailed in most cases.
unknown- These emails we weren't able to validate for one reason or another. Typical cases are "Their mail server was down" or "the anti-spam system is blocking us". In most cases, 80% unknowns are invalid/bad email addresses.

We also provide a sub_status code to help explain some of the unknown and invalid results, not all unknowns and invalids will have sub_status codes.

SUB STATUS EXPLANATION

alias_address- (valid) These emails addresses act as forwarders/aliases and are not real inboxes, for example if you send an email to [email protected] and then the email is forwarded to [email protected]. It's a valid email address and you can send to them, it's just a little more information about the email address. We can sometimes detect alias email addresses and when we do we let you know.
antispam_system- (unknown) These emails have anti-spam systems deployed that are preventing us from validating these emails. You can submit these to us through the contact us screen to look into.
does_not_accept_mail- (invalid) These domains only send mail and don't accept it.
exception_occurred- (unknown) These emails caused an exception when validating. If this happens repeatedly, please let us know.
failed_smtp_connection- (unknown) These emails belong to a mail server that won't allow an SMTP connection. Most of the time, these emails will end up being invalid.
failed_syntax_check- (Invalid) Emails that fail RFC syntax protocols
forcible_disconnect- (Unknown) These emails belong to a mail server that disconnects immediately upon connecting. Most of the time, these emails will end up being invalid.
global_suppression- (do_not_mail) These emails are found in many popular global suppression lists (GSL), they consist of known ISP complainers, direct complainers, purchased addresses, domains that don't send mail, and known litigators.
greylisted- (Unknown) Emails where we are temporarily unable to validate them. A lot of times if you resubmit these emails they will validate on a second pass.
leading_period_removed- (valid) If a valid gmail.com email address starts with a period '.' we will remove it, so the email address is compatible with all mailing systems.
mail_server_did_not_respond- (unknown) These emails belong to a mail server that is not responding to mail commands. Most of the time, these emails will end up being invalid.
mail_server_temporary_error- (unknown) These emails belong to a mail server that is returning a temporary error. Most of the time, these emails will end up being invalid.
mailbox_quota_exceeded- (invalid) These emails exceeded their space quota and are not accepting emails. These emails are marked invalid.
mailbox_not_found- (invalid) These emails addresses are valid in syntax, but do not exist. These emails are marked invalid.
no_dns_entries- (invalid) These emails are valid in syntax, but the domain doesn't have any records in DNS or have incomplete DNS Records. Therefore, mail programs will be unable to or have difficulty sending to them. These emails are marked invalid.
possible_trap- (do_not_mail) These emails contain keywords that might correlate to possible spam traps like spam@ or @spamtrap.com. Examine these before deciding to send emails to them or not.
possible_typo- (invalid) These are emails of commonly misspelled popular domains. These emails are marked invalid.
role_based- (do_not_mail) These emails belong to a position or a group of people, like sales@ info@ and contact@. Role-based emails have a strong correlation to people reporting mails sent to them as spam and abuse.
role_based_catch_all- (do_not_mail) These emails are role-based and also belong to a catch_all domain.
timeout_exceeded- (unknown) These emails belong to a mail server that is responding extremely slow. Most of the time, these emails will end up being invalid.
unroutable_ip_address- (invalid) These emails domains point to an un-routable IP address, these are marked invalid.
disposable- (do_not_mail) These are temporary emails created for the sole purpose to sign up to websites without giving their real email address. These emails are short lived from 15 minutes to around 6 months. There is only 2 values (True and False). If you have valid emails with this flag set to TRUE, you shouldn't email them.
toxic- (do_not_mail) These email addresses are known to be abuse, spam, or bot created emails. If you have valid emails with this flag set to TRUE, you shouldn't email them.
alternate- (valid) These emails are valid, but they are likely to be secondary addresses for the users. Alternate emails are often used to sign up for accounts but otherwise do not see much engagement. As opposed to primary email addresses, which would look more formal, alternate emails will usually contain numbers or more special characters, e.g [email protected]. Identifying alternate email addresses allows for better email list segmentation. Users with formal emails are more likely to engage with your content.

We also provide other additional fields that you should take into consideration before emailing. If any of your valid emails have the disposable or toxic flag set to true, we recommend that you don't email them.

OTHER FIELDS

free_email- [true/false] If the email comes from a free provider.
mx_found- [true/false] Does the domain have an MX record.
mx_record- The preferred MX record of the domain.

smtp_provider- The SMTP Provider of the email or [null].

Contact Us for Any Assistance

If you have any questions or need assistance, please reach out to our customer support team. You can contact us via email at [email protected]. We strive to provide prompt and reliable assistance, ensuring your queries are addressed effectively.

We value your feedback and are committed to making your experience smooth and enjoyable. Our team is dedicated to assisting you with any needs you may have. Thank you for choosing our services. We look forward to helping you!