Email Validation & Verification in .NET

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.

var client = new IpApiClient(Environment.GetEnvironmentVariable("IP_API_IO_KEY")!);

var info = await client.EmailInfoAsync("user@example.com");

Console.WriteLine(info.Syntax.IsValid); // True
Console.WriteLine(info.IsDisposable);   // False
Console.WriteLine(info.HasMxRecords);   // True
if (info.MxRecords.FirstOrDefault() is { } record)
    Console.WriteLine(record.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.

var result = await client.ValidateEmailAsync("user@example.com");

Console.WriteLine(result.Reachable); // "yes" | "no" | "unknown"
if (result.Smtp is { } smtp)
    Console.WriteLine($"{smtp.Deliverable} {smtp.CatchAll}");
Console.WriteLine(result.Disposable);  // False
Console.WriteLine(result.RoleAccount); // False  (e.g. info@, support@)
Console.WriteLine(result.Free);        // False  (e.g. gmail.com)
if (result.Suggestion is { } suggestion)
    Console.WriteLine(suggestion);     // typo fix, e.g. "user@gmail.com"

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

var batch = await client.ValidateEmailBatchAsync(
    new[] { "user@example.com", "fake@mailinator.com" });

Console.WriteLine(batch.TotalProcessed);        // 2
Console.WriteLine(batch.SuccessfulValidations); // 2

foreach (var (email, result) in batch.Results)
    Console.WriteLine($"{email} {result.Reachable} {result.Disposable}");