SparkPost Recipient Validation is now available both for existing SparkPost customers and for new, non-sending customers. It uses powerful data-driven analysis on billions of bounce, delivery, and engagement events daily to train our algorithm, bringing you one of the most powerful data-driven email validation tools on the market, so you can send emails smarter.

Este artículo explains how you can get the most out of the data you’ll receive back on each validated recipient – you’ll see we classify addresses to be “valid”, “risky”, “neutral”, “undeliverable”, and “typo”. We give you a “reason” code and also a “did_you_mean” for known address typos.

Solicitudes API

In the SparkPost web app, you can drag & drop an entire list for validation. You can also use la API to validate single addresses, so you can build validation right into your address entry workflow.

A while back we came up with a Herramienta de línea de comandos Python using this API. We talked over what we should do for otros languages – and here we are! Let’s get started.

This Carpeta del repositorio de Github has working Recipient Validation API call examples in around a dozen different languages. We try to cover the idiomas aplicables más populares.

La forma común de trabajar con todos estos ejemplos es:

• Pick up your key from environment variable SPARKPOST_API_KEY

• Make an API call to /api/v1/recipient-validation/single/to validate a recipient

• Recibe de vuelta una cadena de respuesta, que contiene datos con formato JSON con el resultado

• Imprimir el resultado

SparkPost has bibliotecas for some, but not all of the languages covered here. We chose to write these examples “native” instead, so we could a) cover more languages, b) show how simple the underlying code can be, and c) enable you to see clearly the similarities and differences between languages.

Bash / Rizo

Esto gana el premio al código más corto - simplemente utiliza la herramienta de línea de comandos "curl" para hacer la petición e imprimir la respuesta directamente en el terminal. Puedes ver que la salida es una cadena, que contiene JSON; en realidad no analizamos los atributos individuales de los resultados.

PHP

Trusty PHP has a few different vías to make HTTPS API calls. Here we chose to use curl_setopt and curl_exec. (https://www.php.net/manual/en/function.curl-exec.php)

If you prefer Petición HTTP2 or pecl_http, then Postman has a built-in code generator that you can use to create similar examples – just set up a working GET request and use the “Code” button.

Python

This uses the popular requests module, which is high-level and therefore easy to use. This example checks the returned status code, converts the results JSON back into a Python dictionary object, and prints the resulting object rather than just a string.

If you prefer the built-in http.client library, Postman can generate code for that too; it’s not much longer.

Node.js

There are diferentes node.js HTTP(S) libraries. I started with the older request package (using a callback function) but it’s deprecated and no longer actively maintained.  I chose the newer axios package (using promete). 

Postman can also give you a Javascript native example and Unirest, in case you prefer those.

Dado que este código necesita acceder a su clave API, le recomendamos encarecidamente que llame a nuestra API desde el lado del servidor, nunca desde el lado del cliente (navegador / dispositivo móvil).

Go

Go strives toward a philosophy of “one good way” to do something; in this case, using the built-in “batteries included” libraries net/http, encoding/json and others.

En length is due mostly a la explicit error checking clauses if err != nil {} everywhere (sin excepciones LOL).

También declaramos la estructura del objeto de resultados con etiquetas de campo, para permitirnos "desmarcar" la cadena JSON devuelta. Superponemos las etiquetas "resultados" y "errores" para permitir ambos tipos de devolución.

Me gusta la velocidad, la seguridad de tipos y la claridad de Go, aunque el código sea más largo que en nuestros ejemplos anteriores.

C#

I’m less familiar with C# – to me, it looks quite Java-like, rather than C-like. I was able to put this together following examples shown in the request library System.Net.Http.

Postman can auto-generate example code using RestSharp, if you prefer that.

Ruby

This was my first attempt at Ruby code; I used the Red::http library, and followed este ejemplo (which turns out to be very close a la code that Postman auto-generates).

I ran into one language / library oddity that’s worth explaining. Just setting up using a URI that begins “https://” is not enough, you have to specifically set http.use_ssl = true. 

Sin esto, tu código intentará una petición en el puerto 443 - pero sin usar SSL/TLS (es decir, en plain), y SparkPost se negará correctamente a autorizar la petición. No intente esto en casa, porque su clave de API está en el encabezado de autorización. Esta característica del lenguaje / biblioteca me pareció insegura.

Java

I’ve not written any serious Java before, but it was easy to piece this together by following the general approach used in the Biblioteca SparkPost for other GET calls.

Incidentally, using VS Code as my editor / debugger worked really well for all the languages here, giving me syntax highlighting, debugger stepping / variables viewing etc. El InputStreamReaderand BufferedReaderconstructs are similar to (and I assume were copied by) Go.

C / C++

This was a trip down memory lane, as I wrote a lot of C code in the 1990s, some still running deep in telecoms networks somewhere. As the historia de C predates the modern Web, it’s not surprising that library support is a manual task. We need to download (and compile) a recent version of Libcurl, linking to an OpenSSL library – see the LÉAME for actual steps.

Esto se siente como un montón de trabajo en comparación con los lenguajes modernos, sobre todo cuando Go (o Lua, o Python, o cualquiera de los otros) son lo suficientemente rápidos para tareas como esta.

En other thing I had forgotten, despite bearing the scars from previous battles, is the scariness of memory allocation! To keep the example simple, I preallocated the URL string length as 1024 characters, and bounds-checked the email address length (using strlen) before we concatenate into it (using strcat).

Tratamos la cadena de Autorización con una clave API concatenada de la misma manera .. aunque sabemos que una clave API válida nunca será demasiado larga .. ¡eso no es protección! La entrada del usuario proveniente de una variable de entorno podría ser cualquier cosa. Debes programar a la defensiva.

A more sophisticated developer might use mallocinstead of stack variable allocation, and calculate just how long the joined strings need to be. Having to think about this extra complexity gave me a dolor en los diodos de mi lado izquierdo; it reminded me of the risks that C programmers run every day, trying to avoid buffer overruns and unexpected side-effects. Which brings us to ..

Lua

Lua is known for its easy coexistence alongside a body of C code, and here at SparkPost, we utiliza Lua de forma extensiva for Policy customisations inside our Momentum on-premises MTA. You can also use it as a stand-alone scripting language, and it’s pretty nice for that, too.

With Lua 5.3 and the luarocks package manager, we use libraries luasocket and luasec. Showing its C integration heritage, we link to our local OpenSSL library. The luarocks install process calls the gcc compiler (or whatever C compiler you are using), so adding new libraries takes a while.

The Lua code is quite simple. The characters — mark comments.  The function https.request provides múltiples valores de retorno (a bit like Python and Go). String concatenation is done with the operador  .. (instead of + in Python).

The response body from this call is handled with the “ltn12” module – see here. That enables efficient handling of data that could be returned in multiple “chunks”. As that article explains:

La fábrica de tablas crea un sumidero que almacena todos los datos obtenidos en una tabla. Posteriormente, los datos pueden concatenarse de forma eficiente en una única cadena con la función de la biblioteca table.concat.

Nuestro ejemplo sólo concatena la tabla t y la imprime; podrías utilizar un filtro para realizar más procesamientos.

Perl

While Perl is famous for its frases hechas, this is not one of them.  Perl was designed for very fast document search and modification, but is actually capable of so much more.  I once wrote an entire Inventory control suite in Perl.  Go figure.   A n y w a y…

This script makes use of LWP::UserAgent and HTTP::Request and optionally the JSON and Data::Dumper packages depending on how you want to see the output. As with all the other scripts on this page, you should pre-set an environment variable SPARKPOST_API_KEYto your generated API key that includes the Recipient Validation function. This script hard codes $recipient = ‘test@gmail.com’ but you can easily add command-line input or consume from a file.

After all the variables are populated, we load an HTTP:Request with GET parameters and send it to the LWP:UserAgent.  The resulting “message” is the result of the email validation test as an array.  You can use JSON and DUMPER to display the result or just pass the array on for additional processing.

VB.net

Visual Basic is not visual and it is not basic (IMHO), but it is #6 on the Índice de lenguas TIOBE so here we go.

There are other ways to do this, but the easiest path to success is to use the Visual Studio SDK in a Windows platform. Fire up Visual Studio, start a new project and select Visual Basic, then select console.app.  Be sure to use the VB version not the C# version – it is easy to miss that in the SDK.

At this point you can edit lines manually or copy/paste the code desde aquí into VS and save a bunch of time. In order to make this code work, you need to add a Windows environment variable.  The easiest way to do this is to open a command prompt and use setx.exe like this: 

C:\Users\me>setx SPARKPOST_API_KEY  "142<redacted<redacted>c531c3"

En Windows 10, esto se aplica a tu entorno de usuario, pero no está disponible inmediatamente en la sesión de comandos actual, por lo que probarlo con un "set" no funcionará, pero estará disponible para el código. Si construyes y ejecutas el código incluido en el repo, verás el resultado de la validación.

Óxido

Rust is a language for systems and web-services programming that is focused on performance, safety and concurrency. As Wikipedia says, Rust has been the “most loved programming language” in the Stack Overflow Developer Survey since 2016.

The Rust code en nuestro repositorio de Github uses the reqwest library with tokio async, similar to this example from the Rust cookbook. (That’s not a typo, the reqwest library name is spelled like that). We’ve included a cargo package manager archivo de configuración, so you can build and run with:

cd rust_recipient_validation cargo run

Esto compilará el paquete en código ejecutable y lo ejecutará:

Finished dev [unoptimized + debuginfo] target(s) in 0.10s Running `target/debug/rust_recipient_validation` Status: 200 OK Body: : (etc)

The code uses std:entornoto read the SPARKPOST_API_KEY environment variable. A match clause handles the case where the key is undefined. If all is well, a new reqwest::Cliente is created and an async call issued, followed by an .¿esperar? (see here). Async, rather than the simpler blocking call, seems to be needed to set request headers. Response body text is read with a second .¿esperar?, as per este ejemplo.

Summary

En este artículo, hemos recorrido ejemplos de código de Validación de Destinatario en muchos idiomas. Esto es lo que te pedimos.

Let us know if you think we missed your favorite language. We may not have as many examples as El proyecto Fibonacci, but we’d love to add some more. Also, if you think our examples can be improved, let us know!