upgraded govalidator to v10 and added EmailFormat validation rule

README.md

@@ -422,7 +422,7 @@ The following code implements the aforementioned examples:
 result := validation.ValidateStruct(&a,
     validation.Field(&a.Unit, validation.When(a.Quantity != "", validation.Required).Else(validation.Nil)),
     validation.Field(&a.Phone, validation.When(a.Email == "", validation.Required.Error('Either phone or Email is required.')),
-	validation.Field(&a.Email, validation.When(a.Phone == "", validation.Required.Error('Either phone or Email is required.')),
+    validation.Field(&a.Email, validation.When(a.Phone == "", validation.Required.Error('Either phone or Email is required.')),
 )
 ```
 
@@ -470,7 +470,8 @@ of a value satisfies certain requirements. Note that these rules only handle str
  or byte slice is empty, it is considered valid. You may use a `Required` rule to ensure a value is not empty.
 Below is the whole list of the rules provided by the `is` package:
 
-* `Email`: validates if a string is an email or not
+* `Email`: validates if a string is an email or not. It also checks if the MX record exists for the email domain.
+* `EmailFormat`: validates if a string is an email or not. It does NOT check the existence of the MX record.
 * `URL`: validates if a string is a valid URL
 * `RequestURL`: validates if a string is a valid request URL
 * `RequestURI`: validates if a string is a valid request URI

go.mod

@@ -3,6 +3,6 @@ module github.com/go-ozzo/ozzo-validation/v4
 go 1.13
 
 require (
+	github.com/asaskevich/govalidator v0.0.0-20200108200545-475eaeb16496
 	github.com/stretchr/testify v1.4.0
-	gopkg.in/asaskevich/govalidator.v9 v9.0.0-20180315120708-ccb8e960c48f
 )

go.sum

@@ -1,3 +1,5 @@
+github.com/asaskevich/govalidator v0.0.0-20200108200545-475eaeb16496 h1:zV3ejI06GQ59hwDQAvmK1qxOQGB3WuVTRoY0okPTAv0=
+github.com/asaskevich/govalidator v0.0.0-20200108200545-475eaeb16496/go.mod h1:oGkLhpf+kjZl6xBf758TQhh5XrAeiJv/7FRz/2spLIg=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -6,8 +8,6 @@ github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
-gopkg.in/asaskevich/govalidator.v9 v9.0.0-20180315120708-ccb8e960c48f h1:RVvpqSdNKxt6sENjmw0kdyyv8r18TdpmYTrvUUg2qkc=
-gopkg.in/asaskevich/govalidator.v9 v9.0.0-20180315120708-ccb8e960c48f/go.mod h1:+MTrBL6wlsxv1uFXT6b9LWG7PJdrvUJEjl8tXOlk9OU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=

is/rules.go

@@ -10,7 +10,7 @@ import (
 	"regexp"
 	"unicode"
 
-	"gopkg.in/asaskevich/govalidator.v9"
+	"github.com/asaskevich/govalidator"
 )
 
 var (
@@ -125,8 +125,10 @@ var (
 )
 
 var (
-	// Email validates if a string is an email or not.
-	Email = validation.NewStringRuleWithError(govalidator.IsEmail, ErrEmail)
+	// Email validates if a string is an email or not. It also checks if the MX record exists for the email domain.
+	Email = validation.NewStringRuleWithError(govalidator.IsExistingEmail, ErrEmail)
+	// EmailFormat validates if a string is an email or not. Note that it does NOT check if the MX record exists or not.
+	EmailFormat = validation.NewStringRuleWithError(govalidator.IsEmail, ErrEmail)
 	// URL validates if a string is a valid URL
 	URL = validation.NewStringRuleWithError(govalidator.IsURL, ErrURL)
 	// RequestURL validates if a string is a valid request URL

is/rules_test.go

@@ -20,6 +20,7 @@ func TestAll(t *testing.T) {
 		err            string
 	}{
 		{"Email", Email, "[email protected]", "example.com", "must be a valid email address"},
+		{"EmailFormat", EmailFormat, "[email protected]", "example.com", "must be a valid email address"},
 		{"URL", URL, "http://example.com", "examplecom", "must be a valid URL"},
 		{"RequestURL", RequestURL, "http://example.com", "examplecom", "must be a valid request URL"},
 		{"RequestURI", RequestURI, "http://example.com", "examplecom", "must be a valid request URI"},