Email Validation & Verification in Rust

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.

let client = Client::new(std::env::var("IP_API_IO_KEY")?);

let info = client.email_info("user@example.com").await?;

println!("{}", info.syntax.is_valid); // true
println!("{}", info.is_disposable);   // false
println!("{}", info.has_mx_records);  // true
if let Some(record) = info.mx_records.first() {
    println!("{}", 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.

let result = client.validate_email("user@example.com").await?;

println!("{}", result.reachable); // "yes" | "no" | "unknown"
if let Some(smtp) = &result.smtp {
    println!("{} {}", smtp.deliverable, smtp.catch_all);
}
println!("{}", result.disposable);   // false
println!("{}", result.role_account); // false  (e.g. info@, support@)
println!("{}", result.free);         // false  (e.g. gmail.com)
if let Some(suggestion) = &result.suggestion {
    println!("{suggestion}");        // typo fix, e.g. "user@gmail.com"
}

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

let batch = client
    .validate_email_batch(&["user@example.com", "fake@mailinator.com"])
    .await?;

println!("{}", batch.total_processed);        // 2
println!("{}", batch.successful_validations); // 2

for (email, result) in &batch.results {
    println!("{email} {} {}", result.reachable, result.disposable);
}