Email Validation & Verification in Go

A lightweight check (no SMTP probe): validates syntax, confirms the domain has MX records, and flags disposable/throwaway providers. Use it inline on sign-up forms.

client := ipapi.NewClient(ipapi.WithAPIKey(os.Getenv("IP_API_IO_KEY")))
ctx := context.Background()

info, err := client.EmailInfo(ctx, "user@example.com")
if err != nil {
	log.Fatal(err)
}

fmt.Println(info.Syntax.IsValid) // true
fmt.Println(info.IsDisposable)   // false
fmt.Println(info.HasMXRecords)   // true
if len(info.MXRecords) > 0 {
	fmt.Println(info.MXRecords[0].Hostname)
}

Advanced verification that connects to the mail server to confirm the mailbox is deliverable, and adds role-account, free-provider, catch-all and Gravatar signals.

result, _ := client.ValidateEmail(ctx, "user@example.com")

fmt.Println(result.Reachable) // "yes" | "no" | "unknown"
if result.SMTP != nil {
	fmt.Println(result.SMTP.Deliverable, result.SMTP.CatchAll)
}
fmt.Println(result.Disposable)  // false
fmt.Println(result.RoleAccount) // false  (e.g. info@, support@)
fmt.Println(result.Free)        // false  (e.g. gmail.com)
fmt.Println(result.Suggestion)  // typo fix, e.g. "user@gmail.com"

Advanced-validate up to 100 addresses in one request — the building block for email list cleaning. Returns an error if the slice is empty or longer than 100.

batch, _ := client.ValidateEmailBatch(ctx, []string{
	"user@example.com",
	"fake@mailinator.com",
})

fmt.Println(batch.TotalProcessed)        // 2
fmt.Println(batch.SuccessfulValidations) // 2

for email, result := range batch.Results {
	fmt.Println(email, result.Reachable, result.Disposable)
}