Email component, IMAP component, POP3 component for .NET

Mail.dll is a powerful .NET IMAP component and POP3 component designed for developers who need to receive and process emails in their .NET applications. This comprehensive library includes a robust SMTP component for reliable email sending.

With Mail.dll, you can sign and encrypt emails using the S/MIME standard, ensuring secure communication. The component also supports signature verification and decryption, providing a full suite of tools for handling email security in received messages.

Enhance your .NET applications with Mail.dll for efficient and secure e-mail processing.

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The library fully supports async/await API for building scalable and responsive applications.

Written entirely in managed code. Mail.dll only requires the .NET be installed on the machine.

It supports both C# and VB.NET languages. Works with .NET framework 2.0-4.8, .NET Core 2.0+, .NET Standard 2.0+, .NET 5.0/.NET 8.0 and newer including ASP.NET Core and Azure.

Mail.dll features

.NET IMAP client for receiving emails, .NET POP3 client for receiving emails
.NET SMTP client for sending emails in a single package
UNIQUE Email component includes most reliable MIME parser on the market
UNIQUE Covered with 6 000+ unit and integration tests
Fully compatible with Microsoft Exchange (all versions), Office 365, Gmail, Dovecot, hMailServer and others
SSL/TLS (incl. TLS 1.2 and TLS 1.3) are supported
Automatic email attachment encoding and decoding
S/MIME: sending signed emails, sending encrypted emails
S/MIME: received signed emails validation, received emails decryption
UNIQUE Received emails DKIM validation and signing
UNIQUE Full support of iCalendar appointments and vCards
Outlook .msg files processing and .msg to MIME converter
TNEF support (decode winmail.dat files automatically)
Easily create and save attachments using a file or byte array
Secure login (APOP, CRAM-MD5, DIGEST-MD5 support)
Proxy support: HTTP and Socks proxy (Socks5, Socks4, Socks4a)
IMAP IDLE: push email support for IMAP client
UNIQUE Includes an easy to use template engine
Support for displaying emails in Windows applications
UNIQUE OAuth 2.0 for web sites (ASP.NET) and OAuth 2.0 for installed applications support
UNIQUE IMAP protocol Gmail extensions
Bounce handling for emails received with IMAP and POP3
Bayesian anti-spam filter (over 99.5% accuracy)
UNIQUE Build-in HTML email to plain text email converter

Clients about Mail.dll

Just bought a license. Mail.dll is an absolutely fantastic email library. I would recommend it to anyone who needs to send or receive emails from .NET applications

I like your product. I should also recognize the excellent technical support you provide; my questions were always promptly answered, and the answers were very helpful every time.

I’ve installed 4 or so other email components from other vendors, played with each of them to see how easy they are to work with, and yours was up and running quicker, easier, and better than all the others.

Quick start .NET samples

Receive emails using IMAP in .NET

    using(Imap imap = new Imap())
    {
        imap.ConnectSSL("imap.server.com");
        imap.UseBestLogin("user", "pass");
    
        imap.SelectInbox();

        List<long> uids = imap.Search(
            Flag.Unseen);
        long first = uids[0];
        
        byte[] eml = imap
            .GetMessageByUID(first);
        
        IMail email = new MailBuilder()
            .CreateFromEml(eml);
        
        string subject = email.Subject;
        
        imap.Close();
    }

Receive emails using POP3 in .NET

    using(Pop3 pop3 = new Pop3())
    {
        pop3.ConnectSSL("imap.server.com");
        pop3.UseBestLogin("user", "pass");
    
        List<long> uids = pop3.GetAll();
        long first = uids[0];
        
        byte[] eml = pop3
            .GetMessageByUID(first);
        
        IMail email = new MailBuilder()
            .CreateFromEml(eml);
        
        string subject = email.Subject;
        
        pop3.Close();
    }

C#
VB.NET

Receive emails using IMAP with C# .NET client

	            using(Imap imap = new Imap())
                {
                    imap.ConnectSSL("imap.server.com");  // or Connect for non SSL/TLS
                    imap.UseBestLogin("user", "password");

                    imap.SelectInbox();

                    List<long> uids = imap.Search(Flag.Unseen);
                    foreach (long uid in uids)
                    {
                        IMail email = new MailBuilder()
                            .CreateFromEml(imap.GetMessageByUID(uid));
                        string subject = mail.Subject;
                    }
                    imap.Close();
                }

Receive emails using POP3 with C# .NET client

                using(Pop3 pop3 = new Pop3())
                {
                    pop3.ConnectSSL("pop3.server.com");  // or Connect for non SSL/TLS 
                    pop3.UseBestLogin("user", "password");

                    List<string> uids = pop3.GetAll();
                    foreach (string uid in uids)
                    {
                        IMail email = new MailBuilder()
                            .CreateFromEml(pop3.GetMessageByUID(uid));
                        string subject = email.Subject;
                    }
                    pop3.Close();
                }

Send emails using SMTP with C# .NET client

				
				MailBuilder builder = new MailBuilder();
				builder.From.Add(new MailBox("from@example.com"));
				builder.To.Add(new MailBox("to@example.com"));
				builder.Subject = "Subject";
				builder.Html = @"Html with an image: <img src=""cid:lena"" />";

				var visual = builder.AddVisual(@"c:\lena.jpeg");
				visual.ContentId = "lena";
				var attachment = builder.AddAttachment(@"c:\tmp.doc");
				attachment.SetFileName("document.doc", guessContentType: true);

				IMail email = builder.Create();

                using(Smtp smtp = new Smtp())
                {
                    smtp.Connect("smtp.server.com");  // or ConnectSSL for SSL
                    smtp.UseBestLogin("user", "password");

                    smtp.SendMessage(email);                      
                    smtp.Close();    
                }

Receive emails using POP3 with VB.NET client

                Using imap As New Imap
                    imap.ConnectSSL("imap.server.com")  ' or Connect for non SSL/TLS
                    imap.UseBestLogin("user", "password")

                    imap.SelectInbox()

                    Dim uidList As List(Of Long) = imap.Search(Flag.Unseen)
                    For Each uid As Long In uidList
                        Dim email As IMail = New MailBuilder() _
                            .CreateFromEml(imap.GetMessageByUID(uid))
                        Dim subject As String = email.Subject
                    Next
                    imap.Close()
                End Using

Receive emails using POP3 with VB.NET client

                Using pop3 As New Pop3
                    pop3.ConnectSSL("pop3.server.com")  ' or Connect for non SSL/TLS  
                    pop3.UseBestLogin("user", "password")

                    For Each uid As String In pop3.GetAll()
                        Dim email As IMail = New MailBuilder() _
                            .CreateFromEml(pop3.GetMessageByUID(uid))
                        Dim subject As String = email.Subject
                    Next
                    pop3.Close()
                End Using

Send emails using SMTP with VB.NET client

			    Dim builder As MailBuilder = New MailBuilder()
			    builder.From.Add(New MailBox("from@example.com"))
			    builder.[To].Add(New MailBox("to@example.com"))
			    builder.Subject = "Subject"
			    builder.Html = "Html with an image: <img src=""cid:lena"" />"
			    
				Dim visual = builder.AddVisual("c:\lena.jpeg")
			    visual.ContentId = "lena"
			    Dim attachment = builder.AddAttachment("c:\tmp.doc")
			    attachment.SetFileName("document.doc", guessContentType:=True)

			    Dim email As IMail = builder.Create()

                Using smtp As Smtp = New Smtp
                    smtp.Connect("smtp.server.com")  ' or ConnectSSL for SSL
                    smtp.UseBestLogin("user", "password")

                    smtp.SendMessage(email)
                    smtp.Close()
                End Using

You can find many more .NET email client samples here.