email-verifier
✉️ A Go library for email verification without sending any emails.
Features
- Email Address Validation: validates if a string contains a valid email.
- Email Verification Lookup via SMTP: performs an email verification on the passed email
- MX Validation: checks the DNS MX records for the given domain name
- Misc Validation: including Free email provider check, Role account validation, Disposable emails address (DEA) validation
- Email Reachability: checks how confident in sending an email to the address
Install
Use go get
to install this package.
go get -u github.com/AfterShip/email-verifier
Usage
Basic usage
Use Verify
method to verify an email address with different dimensions
package main
import (
"fmt"
emailverifier "github.com/AfterShip/email-verifier"
)
var (
verifier = emailverifier.NewVerifier()
)
func main() {
email := "example@exampledomain.org"
ret, err := verifier.Verify(email)
if err != nil {
fmt.Println("verify email address failed, error is: ", err)
return
}
if !ret.Syntax.Valid {
fmt.Println("email address syntax is invalid")
return
}
fmt.Println("email validation result", ret)
/*
result is:
{
"email":"example@exampledomain.org",
"disposable":false,
"reachable":"unknown",
"role_account":false,
"free":false,
"syntax":{
"username":"example",
"domain":"exampledomain.org",
"valid":true
},
"has_mx_records":true,
"smtp":null,
"gravatar":null
}
*/
}
Email verification Lookup
Use CheckSMTP
to performs an email verification lookup via SMTP.
var (
verifier = emailverifier.
NewVerifier().
EnableSMTPCheck()
)
func main() {
domain := "domain.org"
username := "username"
ret, err := verifier.CheckSMTP(domain, username)
if err != nil {
fmt.Println("check smtp failed: ", err)
return
}
fmt.Println("smtp validation result: ", ret)
}
Note: because most of the ISPs block outgoing SMTP requests through port 25 to prevent email spamming, the module will not perform SMTP checking by default. You can initialize the verifier with
EnableSMTPCheck()
to enable such capability if port 25 is usable, or use a socks proxy to connect over SMTP
Use a SOCKS5 proxy to verify email
Support setting a SOCKS5 proxy to verify the email, proxyURI should be in the format: socks5://user:password@127.0.0.1:1080?timeout=5s
The protocol could be socks5, socks4 and socks4a.
var (
verifier = emailverifier.
NewVerifier().
EnableSMTPCheck().
Proxy("socks5://user:password@127.0.0.1:1080?timeout=5s")
)
func main() {
domain := "domain.org"
username := "username"
ret, err := verifier.CheckSMTP(domain, username)
if err != nil {
fmt.Println("check smtp failed: ", err)
return
}
fmt.Println("smtp validation result: ", ret)
}
Misc Validation
To check if an email domain is disposable via IsDisposable
var (
verifier = emailverifier.
NewVerifier().
EnableAutoUpdateDisposable()
)
func main() {
domain := "domain.org"
if verifier.IsDisposable(domain) {
fmt.Printf("%s is a disposable domain\n", domain)
return
}
fmt.Printf("%s is not a disposable domain\n", domain)
}
Note: It is possible to automatically update the disposable domains daily by initializing verifier with
EnableAutoUpdateDisposable()
Suggestions for domain typo
Will check for typos in an email domain in addition to evaluating its validity.
If we detect a possible typo, you will find a non-empty "suggestion" field in the validation result containing what we believe to be the correct domain.
Also, you can use the SuggestDomain()
method alone to check the domain for possible misspellings
func main() {
domain := "gmai.com"
suggestion := verifier.SuggestDomain(domain)
// suggestion should be `gmail.com`
if suggestion != "" {
fmt.Printf("domain %s is misspelled, right domain is %s. \n", domain, suggestion)
return
}
fmt.Printf("domain %s has no possible misspellings. \n", domain)
}
Note: When using the
Verify()
method, domain typo checking is not enabled by default, you can enable it in a verifier withEnableDomainSuggest()
For more detailed documentation, please check on godoc.org 👉 email-verifier
API
We provide a simple self-hosted API server script for reference.
The API interface is very simple. All you need to do is to send a GET request with the following URL.
The email
parameter would be the target email you want to verify.
https://{your_host}/v1/{email}/verification
Similar Libraries Comparison
email-verifier | trumail | check-if-email-exists | freemail | |
---|---|---|---|---|
Features | 〰️ | 〰️ | 〰️ | 〰️ |
Disposable email address validation | ✅ | ✅, but not available in free lib | ✅ | ✅ |
Disposable address autoupdate | ✅ | 🤔 | ❌ | ❌ |
Free email provider check | ✅ | ✅, but not available in free lib | ❌ | ✅ |
Role account validation | ✅ | ❌ | ✅ | ❌ |
Syntax validation | ✅ | ✅ | ✅ | ❌ |
Email reachability | ✅ | ✅ | ✅ | ❌ |
DNS records validation | ✅ | ✅ | ✅ | ❌ |
Email deliverability | ✅ | ✅ | ✅ | ❌ |
Mailbox disabled | ✅ | ✅ | ✅ | ❌ |
Full inbox | ✅ | ✅ | ✅ | ❌ |
Host exists | ✅ | ✅ | ✅ | ❌ |
Catch-all | ✅ | ✅ | ✅ | ❌ |
Gravatar | ✅ | ✅, but not available in free lib | ❌ | ❌ |
Typo check | ✅ | ✅, but not available in free lib | ❌ | ❌ |
Use proxy to connect over SMTP | ✅ | ❌ | ✅ | ❌ |
Honeyport dection | 🔜 | ❌ | ❌ | ❌ |
Bounce email check | 🔜 | ❌ | ❌ | ❌ |
Tech | 〰️ | 〰️ | 〰️ | 〰️ |
Provide API | ✅ | ✅ | ✅ | ❌ |
Free API | ✅ | ❌ | ❌ | ❌ |
Language | Go | Go | Rust | JavaScript |
Active maintain | ✅ | ❌ | ✅ | ✅ |
High Performance | ✅ | ❌ | ✅ | ✅ |
FAQ
The library hangs/takes a long time after 30 seconds when performing email verification lookup via SMTP
Most ISPs block outgoing SMTP requests through port 25 to prevent email spamming. email-verifier
needs to have this port open to make a connection to the email's SMTP server. With the port being blocked, it is not possible to perform such checking, and it will instead hang until timeout error. Unfortunately, there is no easy workaround for this issue.
For more information, you may also visit this StackOverflow thread.
"connection refused"
in the smtp.error
field.
The output shows This error can also be due to SMTP ports being blocked by the ISP, see the above answer.
What does reachable: "unknown" means
This means that the server does not allow real-time verification of an email right now, or the email provider is a catch-all email server.
Credits
- trumail
- check-if-email-exists
- mailcheck
- disposable domains from ivolo/disposable-email-domains
- free provider data from willwhite/freemail
Contributing
For details on contributing to this repository, see the contributing guide.
License
This package is licensed under MIT license. See LICENSE for details.