go-email-validator / go-email-validator

📧 Golang Email address validator

Library under development (Interfaces may be changed slightly)

Demo on rapidapi.com

Install

go get -u github.com/go-email-validator/go-email-validator

Available validators

[email protected]

• syntaxValidator

  1. NewSyntaxValidator() - mail.ParseAddress from built-in library
  2. NewSyntaxRegexValidator(emailRegex *regexp.Regexp) - validation based on regular expression

• disposableValidator based on mailchecker by default (set is replaceable)

• roleValidator bases on role-based-email-addresses by default (set is replaceable)

• mxValidator

• smtpValidator

  to use proxy connection, DialFunc need to be changed in Checker. There is evsmtp.H12IODial, implementing for h12w.

• banWordsUsernameValidator looks for banned words in username

• blackListEmailsValidator blocked emails from list

• blackListValidator blocked emails with domains from black list

• whiteListValidator accepts only emails from white list

• gravatarValidator check existing of user on gravatar.com

Usage

With builder

package main

import (
  "fmt"
  "github.com/go-email-validator/go-email-validator/pkg/ev"
  "github.com/go-email-validator/go-email-validator/pkg/ev/evmail"
)

func main() {
  // create defaults DepValidator with GetDefaultFactories() as list of validators
  builder := ev.NewDepBuilder(nil).Build()
  /*
     to set another list of initial validators
     builder := NewDepBuilder(&ValidatorMap{
         ev.ValidatorName: ev.Validator,
     }).Build()
  */

  // builder.Set(ev.ValidatorName, NewValidator()) builder
  // builder.Has(names ...ev.ValidatorName) bool
  // builder.Delete(names ...ev.ValidatorName) bool

  validator := builder.Build()

  v := validator.Validate(NewInput(evmail.FromString("[email protected]")))
  if !v.IsValid() {
    panic("email is invalid")
  }

  fmt.Println(v)
}

Single validator

package main

import (
  "fmt"
  "github.com/go-email-validator/go-email-validator/pkg/ev"
  "github.com/go-email-validator/go-email-validator/pkg/ev/evmail"
)

func main() {
  var v = ev.NewSyntaxValidator().Validate(ev.NewInput(evmail.FromString("[email protected]"))) // ev.ValidationResult

  if !v.IsValid() {
    panic("email is invalid")
  }

  fmt.Println(v)
}

Addition options

To set options for different validators, use NewInput(..., NewKVOption(ValidatorName, Options))

NewInput(
	evmail.FromString("[email protected]"), 
	NewKVOption(SMTPValidatorName, evsmtp.NewOptions(evsmtp.OptionsDTO{
		Port: 465,
    })),
)

Use function New...(...) to create structure instead of public.

How to extend

To add own validator, just implement ev.Validator interface. For validator without dependencies, you can use structure ev.AValidatorWithoutDeps

Decorators

1. WarningsDecorator allows moving errors to warnings and change result of IsValid() in ValidationResult.
2. Cache based on evcahce.Interface, default realization is done for gocache.
   • CacheDecorator saves result of validator. For caching, you can implement evcache.Interface or use gocache implementation by evcache.NewCache. See Test_Cache as example.
   • checkerCacheRandomRCPT for caching of RandomRCPTs request. See Test_checkerCacheRandomRCPT_RandomRCPT_RealCache as example.

Notice, to use msgpack you should have exported fields or implement custom encoding/decoding (doc)

Logger

Package use zap.

To use logging see in log package. Default level is zap.ErrorLevel.

Addition

1. For running workflow locally use act

FAQ

Most Internet Service Providers block outgoing SMTP request.

The StackOverflow thread could be helpful.

To check smtp in telnet

telnet

OPEN gmail-smtp-in.l.google.com 25
EHLO localhost
MAIL FROM: <[email protected]>
rcpt to: <[email protected]>
quit

Some mail providers could put your ip in spam filter.

For example:

1. hotmail.com

Roadmap

• Tests
  • Add functional tests
  • Find way to compare functions in tests
• Add binary release
• Check in spamhaus
• Add misspelled email
• Add DKIM checking
• Add linter in pre-hook and ci
• Do full thread safe library
• Copy features from truemail
  • Extend MX , rfc5321 section 5
  • Host audit features

Inspired by

• EmailValidator

go-email-validator's Issues

DKIM and SPF checking

Libraries for checking:

1. https://github.com/foxcpp/maddy
2. https://github.com/emersion/go-msgauth
3. https://github.com/toorop/go-dkim
4. https://github.com/foxcpp/mailsec-check
5. https://github.com/GlobalCyberAlliance/GCADMARCRiskScanner
6. https://pkg.go.dev/github.com/shuLhan/share/lib/email/dkim
7. https://github.com/driusan/dkim

To get DKIM selector need to create sending script from different domains