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MailSlurp C# Client

Create real email addresses on demand. Send and receive emails and attachments from code and tests using CSharp (C# DotNet Core).

MailSlurp is an email API service that lets you create real email addresses in code. You can then send and receive emails and attachments in C# applications and tests.

// create client
var config = new Configuration();
config.ApiKey.Add("x-api-key", ApiKey);

// create inboxes
var inboxControllerApi = new InboxControllerApi(config);
var inbox1 = inboxControllerApi.CreateInbox();
var inbox2 = inboxControllerApi.CreateInbox();

// send email
inboxControllerApi.SendEmail(inbox1.Id, new SendEmailOptions(
to: new List<string> {inbox2.EmailAddress},
subject: "Test CSharp",
body: "<span>Hello</span>",
isHTML: true

// receive email with wait controller
var email = new WaitForControllerApi(config).WaitForLatestEmail(inbox2.Id, 60000, true);
StringAssert.Contains(email.Body, "Hello");

// list emails in inbox
var emails = inboxControllerApi.GetInboxEmailsPaginated(inbox2.Id);
Assert.AreEqual(emails.TotalElements, 1);


Get started

This section describes how to get up and running with the CSharp client. The client targets DotNet-Core 2.1 and greater. If you need a different target see the .NET Standard targets below or consider calling the REST API.

See the method documentation for a list of all functions

Create API Key

First you'll need an API Key. Create a free account and copy the key from your dashboard.

Install NuGet Package

MailSlurp's CSharp library is hosted on NuGet.

dotnet add mailslurp


dotnet add package mailslurp
dotnet restore

Package Manager

Install-Package mailslurp

Configure client

Once your MailSlurp package is installed you can import the package like so:

using mailslurp.Api;
using mailslurp.Client;
using mailslurp.Model;

Then configure a client with using your API Key.

var configuration = new Configuration();
configuration.ApiKey.Add("x-api-key", YOUR_API_KEY);
configuration.Timeout = 120_000;

Create controllers

You can call API controllers using the corresponding ControllerApi classes.

var apiInstance = new InboxControllerApi(_configuration);

Common controllers

Email usage examples

MailSlurp has many functions. Here are some common uses:

Create an inbox

Inboxes have an ID and a real email address. You can create them using the InboxController. For more information see the creating inboxes guide.

var inboxController = new InboxControllerApi(_configuration);
var inbox = inboxController.CreateInboxWithDefaults();
Assert.That(inbox.EmailAddress, Does.Contain("@mailslurp"));

Inbox options

var options = new CreateInboxDto(
name: "Test inbox",
inboxType: CreateInboxDto.InboxTypeEnum.SMTPINBOX
var inbox = inboxController.CreateInboxWithOptions(options);
Assert.That(inbox.EmailAddress.Contains("@mailslurp"), Is.True);

Get an inbox

// get by id
var inboxDto = inboxController.GetInbox(inbox.Id);
// get by name
var inboxByName = inboxController.GetInboxByName(inboxDto.Name);
Assert.That(inboxByName.Exists, Is.True);
// get by email address
var inboxByEmailAddress = inboxController.GetInboxByEmailAddress(inboxDto.EmailAddress);
Assert.That(inboxByEmailAddress.Exists, Is.True);

Access mailbox using SMTP client

You can access inboxes via IMAP and SMTP:

var imapSmtpAccess = inboxController.GetImapSmtpAccess(inbox.Id);
Assert.Multiple(() =>
Assert.That(imapSmtpAccess.SecureSmtpServerHost, Is.Not.Null);
Assert.That(imapSmtpAccess.SecureSmtpServerPort, Is.GreaterThan(0));
Assert.That(imapSmtpAccess.SecureSmtpUsername, Is.Not.Null);
Assert.That(imapSmtpAccess.SecureSmtpPassword, Is.Not.Null);

Send with SMTP client

var smtpClient = new SmtpClient(imapSmtpAccess.SecureSmtpServerHost)
Port = imapSmtpAccess.SecureSmtpServerPort,
Credentials = new NetworkCredential(userName: imapSmtpAccess.SecureSmtpUsername,
password: imapSmtpAccess.SecureSmtpPassword),
EnableSsl = true
// smtpClient.Send(...);

Can list inboxes

Inboxes are listed in paginated format:

var inboxes = inboxController.GetAllInboxes(page: 0, size: 10);
Assert.Multiple(() =>
// pagination
Assert.That(inboxes.Pageable.PageNumber, Is.EqualTo(0));
Assert.That(inboxes.Pageable.PageSize, Is.EqualTo(10));
// inboxes
var inboxItem = inboxes.Content.First();
Assert.That(inboxItem.EmailAddress, Is.Not.Null);

See the InboxController docs for help.

Delete an inbox


Verify email address

Validate email recipients to maintain a good sender reputation and reduce bounces.

var verificationController = new EmailVerificationControllerApi(_configuration);
var emails = new List<string>
var result = verificationController.ValidateEmailAddressList(new ValidateEmailAddressListOptions(emails));
Assert.Multiple(() =>
Assert.That(result.InvalidEmailAddresses, Does.Contain(""));
Assert.That(result.ValidEmailAddresses, Does.Contain(""));

Upload attachments

To send attachments first upload them. The method returns a list of attachment IDs that can be used when sending.

var attachmentController = new AttachmentControllerApi(_configuration);
var uploadOptions = new UploadAttachmentOptions(
contentType: "text/plain",
filename: "test.txt",
base64Contents: Convert.ToBase64String("hello world"u8.ToArray())
var attachmentIds = attachmentController.UploadAttachment(uploadOptions);

Send emails

You can send an email by first creating an inbox. Then use the inbox ID to send an email from it.

var sendEmailOptions = new SendEmailOptions
To = new List<string>() { recipient.EmailAddress },
Subject = "Hello friend",
Body = "<h1>MailSlurp supports HTML</h1>",
Attachments = attachmentIds,
UseInboxName = true
var sentEmail = inboxController.SendEmailAndConfirm(inbox.Id, sendEmailOptions);
Assert.That(sentEmail.Subject, Does.Contain("Hello"));

See the SendEmailOptions for sending options.

Receive emails

You can fetch and read emails that already exist using the EmailControllerApi. To wait for expected emails to arrive use the WaitForControllerApi to wait for conditions to be met.

You can receive emails using waitFor methods on the WaitForControllerApi class.

var inboxId = recipient.Id;
var waitForController = new WaitForControllerApi(_configuration);
var email = waitForController.WaitForLatestEmail(inboxId: inboxId, timeout: 60_000, unreadOnly: true);
Assert.That(email.Body, Does.Contain("MailSlurp supports HTML"));

You can extract content from email bodies using RegExps:

// imagine that email body is `Your code is: 123` and you want to get the number
var rx = new Regex(@"Your code is: ([0-9]{3})", RegexOptions.Compiled);
var match = rx.Match(email.Body);
var code = match.Groups[1].Value;

Assert.Equal("123", code);

If you are having trouble receiving emails please see the email receiving guide or the inbox not receiving support page.

Email matching

You can wait for matching emails like so:

var matchOptions = new MatchOptions(
conditions: new List<ConditionOption>
condition: ConditionOption.ConditionEnum.HASATTACHMENTS,
value: ConditionOption.ValueEnum.TRUE
matches: new List<MatchOption>
field: MatchOption.FieldEnum.FROM,
should: MatchOption.ShouldEnum.EQUAL,
value: sender
var matchingEmails = waitForController.WaitForMatchingEmails(inboxId: inboxId, timeout: 60_000, count: 1,
matchOptions: matchOptions);
Assert.That(matchingEmails.First().Subject, Does.Contain("Hello"));

Fetch email by ID

var emailController = new EmailControllerApi(_configuration);
var fullEmail = emailController.GetEmail(email.Id);
Assert.That(fullEmail.Attachments, Has.Count.EqualTo(1));

Get sent emails

public void Can_Get_Sent_Emails()

var sentEmailsControllerApi = new SentEmailsControllerApi(_config);
var inboxControllerApi = new InboxControllerApi(_config);

var inbox = inboxControllerApi.CreateInbox();
var sentEmails = sentEmailsControllerApi.GetSentEmails(inboxId:inbox.Id, page:0, size: 20);

Assert.AreEqual(sentEmails.Pageable.PageNumber, 0);
Assert.AreEqual(sentEmails.Pageable.PageSize, 20);

Extract email content

You can extract content using pattern matching with the WaitForController

public void Can_Extract_Codes()

// create an inbox
var inboxControllerApi = new InboxControllerApi(_config);
var inbox = inboxControllerApi.CreateInbox();

// send a code to the inbox
var sendEmailOptions = new SendEmailOptions(
to: new List<string>() {inbox.EmailAddress},
subject: "Welcome email",
body: "Hello. Your code is X-456"
inboxControllerApi.SendEmail(inbox.Id, sendEmailOptions);

// wait for the email to arrive
var waitForController = new WaitForControllerApi(_config);
var emailController = new EmailControllerApi(_config);
var email = waitForController.WaitForLatestEmail(inboxId:inbox.Id, timeout: 30000, unreadOnly: true);
StringAssert.Contains(email.Body, "Hello");

// extract the code
var matchOptions = new ContentMatchOptions(pattern:"Your code is ([A-Z]-[0-9]{3})");
var matchResults = emailController.GetEmailContentMatch(email.Id, matchOptions);
Assert.AreEqual(matchResults.Matches[1], "X-456");

SDK Documentation

See the GitHub source code for more Method Documentation.