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.

Cet article 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.

Demandes API

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

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

This Dossier de dépôt Github has working Recipient Validation API call examples in around a dozen different languages. We try to cover the les langues applicables les plus populaires.

La façon commune de travailler à travers tous ces exemples est :

• Pick up your key from environment variable SPARKPOST_API_KEY

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

• Réception d'une chaîne de réponse, contenant des données formatées en JSON avec le résultat.

• Imprimez le résultat

SparkPost has bibliothèques 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 / Curl

Ce code remporte la palme du code le plus court - il utilise simplement l'outil de ligne de commande "curl" pour effectuer la requête et imprimer la réponse directement dans le terminal. Vous pouvez voir que la sortie est une chaîne, contenant du JSON ; nous n'analysons pas les attributs de résultat individuels.

PHP

Trusty PHP has a few different moyens 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 HTTP_Request2 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 beaucoup de différents 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 promesses). 

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

Étant donné que ce code doit avoir accès à votre clé API, nous vous recommandons vivement d'appeler notre API depuis le côté serveur, jamais depuis le côté client (navigateur / appareil mobile).

Allez sur

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.

Le length is due mostly à la explicit error checking clauses if err != nil {} everywhere (aucune exception LOL).

Nous déclarons également la structure de l'objet de résultats avec des balises de champ, pour nous permettre de "démarsquer" la chaîne JSON retournée. Nous superposons les balises "results" et "errors" pour permettre les deux types de retour.

J'aime la rapidité, la sécurité des types et la clarté de Go, même si le code est plus long que nos exemples précédents.

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 Net::http library, and followed cet exemple (which turns out to be very close à 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. 

Sans cela, votre code tentera une requête sur le port 443 - mais sans utiliser SSL/TLS (c'est-à-dire en clair), et SparkPost refusera à juste titre d'autoriser la requête. N'essayez pas cela chez vous, car votre clé API se trouve dans l'en-tête Authorization. Cette fonctionnalité du langage / de la bibliothèque ne me semblait pas sûre.

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 Bibliothèque 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. Le lecteur 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 l'histoire 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 README for actual steps.

Cela semble être beaucoup de travail par rapport aux langages modernes, en particulier lorsque Go (ou Lua, ou Python, ou n'importe lequel des autres) sont suffisamment rapides pour des tâches comme celle-ci.

Le 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).

Nous traitons la chaîne d'autorisation avec une clé API concaténée de la même manière. Même si nous savons qu'une clé API valide ne sera jamais trop longue, ce n'est pas une protection ! L'entrée utilisateur provenant d'une variable d'environnement peut être n'importe quoi. Vous devez programmer de manière défensive.

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 douleur dans les diodes en bas de mon côté gauche; 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 a utilisé Lua de manière intensive 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 demande.https provides valeurs de retour multiples (a bit like Python and Go). String concatenation is done with the opérateur  .. (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 fabrique de table crée un puits qui stocke toutes les données obtenues dans une table. Les données peuvent ensuite être concaténées efficacement en une seule chaîne de caractères avec la fonction de bibliothèque table.concat.

Notre exemple se contente de concaténer le tableau t et de l'imprimer ; vous pourriez utiliser un filtre pour effectuer un traitement plus poussé.

Perl

While Perl is famous for its billets d'humeur, 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 Index linguistique 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 d'ici 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"

Dans Windows 10, cela est appliqué à votre environnement utilisateur, mais n'est pas immédiatement disponible dans la session de commande actuelle, donc le tester avec un "set" ne fonctionnera pas, mais il sera disponible pour le code. Si vous construisez et exécutez le code inclus dans le repo, vous verrez le résultat de la validation.

Rouille

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 dans notre dépôt 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 fichier de configuration, so you can build and run with:

cd rust_recipient_validation cargo run

Cela compilera le paquet en code exécutable et l'exécutera :

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

The code uses std:envto 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::Client is created and an async call issued, followed by an .attendre ? (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 .attendre ?, as per cet exemple.

Summary

Dans cet article, nous avons parcouru des exemples de code de validation des destinataires dans de nombreuses langues. Voici ce que nous vous demandons.

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