Golang package for email validation.
- Format (simple regexp, see: https://www.w3.org/TR/html5/forms.html#valid-e-mail-address and https://davidcel.is/posts/stop-validating-email-addresses-with-regex/)
- Valid domain
- Valid user: verify if the user and mailbox really exist
Install the Checkmail package
go get github.com/badoux/checkmail
func main() {
err := checkmail.ValidateFormat("ç$€§/az@gmail.com")
if err != nil {
fmt.Println(err)
}
}output: invalid format
func main() {
err := checkmail.ValidateHost("email@x-unkown-domain.com")
if err != nil {
fmt.Println(err)
}
}output: unresolvable host
If host is valid, requires valid SMTP serverHostName (see to online validator) and serverMailAddress to reverse validation
for prevent SPAN and BOTS.
func main() {
var (
serverHostName = "smtp.myserver.com" // set your SMTP server here
serverMailAddress = "validuser@myserver.com" // set your valid mail address here
)
err := checkmail.ValidateHostAndUser(serverHostName, serverMailAddress, "unknown-user-129083726@gmail.com")
if smtpErr, ok := err.(checkmail.SmtpError); ok && err != nil {
fmt.Printf("Code: %s, Msg: %s", smtpErr.Code(), smtpErr)
}
}output: Code: 550, Msg: 550 5.1.1 The email account that you tried to reach does not exist.
Checkmail is licensed under the MIT License.