Send Email using Exchange Web Service - EWS in VB.NET¶

Introduction¶

Exchange Web Services (EWS), an alternative to the MAPI protocol, is a documented SOAP based protocol introduced with Exchange Server 2007. We can use HTTP or HTTPS protocol to send email with Exchange Web Services (EWS) instead of SMTP protocol.

With EASendMail SMTP Component, you do not have to build your EWS SOAP XML request and parse the response. It wraps the SOAP XML and HTTP request automatically. You just need to change the SmtpServer.Protocol property, and then EASendMail uses Web Service protocol to send email. Your server SHOULD be Exchange 2007 or later version; otherwise you cannot use Exchange Web Service protocol.

• SMTP protocol

  Standard SMTP protocol based on TCP/IP, all email servers support this protocol, Exchange Server also supports SMTP protocol. Using SMTP protocol is always recommended.

• Exchange WebDAV

  Exchange WebDAV is a set of methods based on the HTTP protocol to manage users, messages in Microsoft Exchange Server. We can use HTTP or HTTP/HTTPS protocol to send email with Exchange WebDAV instead of SMTP protocol. But since Exchange 2007, WebDAV service is disabled by default, so I only suggest that you use WebDAV protocol in Exchange 2000/2003.

• Exchange Web Service (EWS)

  Exchange Web Services (EWS), an alternative to the MAPI protocol, is a documented SOAP based protocol introduced with Exchange Server 2007. We can use HTTP or HTTPS protocol to send email with Exchange Web Services (EWS) instead of SMTP protocol. I only suggest that you use EWS protocol in Exchange 2007/2010/2013/2016/2019 or later version. Office365 also supports EWS very well.

[VB.NET - Send Email using Exchange Web Service (EWS) - Example]¶

The following example codes demonstrate how to send email using Exchange Web Service (EWS) in VB.NET.

Imports EASendMail ' Add EASendMail namespace

Module Module1

    Sub Main()

        Try
            Dim oMail As New SmtpMail("TryIt")
            ' Set sender email address, please change it to yours
            oMail.From = "test@emailarchitect.net"
            ' Set recipient email address, please change it to yours
            oMail.To = "support@emailarchitect.net"

            ' Set email subject
            oMail.Subject = "test email from VB.NET project"
            ' Set email body
            oMail.TextBody = "this is a test email sent from VB.NET project, do not reply"

            ' Your Exchange server address
            Dim oServer As New SmtpServer("exch.emailarchitect.net")

            ' Set Exchange Web Service protocol (EWS) - Exchange 2007/2010/2013/2016/2019/Office365
            oServer.Protocol = ServerProtocol.ExchangeEWS

            ' User and password for Exchange User authentication
            oServer.User = "test@emailarchitect.net"
            oServer.Password = "testpassword"

            ' By default, Exchange Web Service requires SSL connection
            oServer.ConnectType = SmtpConnectType.ConnectSSLAuto

            Console.WriteLine("start to send email ...")

            Dim oSmtp As New SmtpClient()
            oSmtp.SendMail(oServer, oMail)

            Console.WriteLine("email was sent successfully!")
        Catch ep As Exception
            Console.WriteLine("failed to send email with the following error:")
            Console.WriteLine(ep.Message)
        End Try

    End Sub

End Module

Exchange Server 2007 EWS Issue¶

If you send email to Exchange Server 2007 using EWS. You may get an exception: “Client does not have permissions to send as this sender”. You should add this line in your code:

' Set sender email address, please change it to yours
oMail.From = "test@emailarchitect.net"
' Add this line
oMail.Headers.RemoveKey("From")

That is because Exchange Server 2007 doesn’t allow From header in the email message, the From header will be added by Exchange Server automatically.

Manage Send As Permissions in Exchange 2007/2010/2013¶

If you send email using SMTP protocol and it threw an exception: “Client does not have permissions to send as this sender” with Exchange 2007/2010/2013, please see the following topic:

• Manage Send As Permissions for a Mailbox in Exchange 2007
• Manage Send As Permissions for a Mailbox in Exchange 2010
• Manage Send As Permissions for a Mailbox in Exchange 2013

Next Section

At next section I will introduce how to send email using Exchange WebDAV in VB.