Send Email in VB from Windows Store Apps - XAML - UWP - Tutorial¶

Send email in A simple VB XAML Windows Store App project¶

To better demonstrate how to send email using SMTP protocol, let’s create a VB XAML Windows Store App project at first, and then add the reference of EASendMail in your project.

After you created the project, double click “MainPage.xaml” and use “Toolbox” to put a Button and a TextBlock control on the XAML page. Set Button control name to “btnSend” and set TextBlock control name to “textStatus”.

The source code in MainPage.xaml is like this:

<Page
    x:Class="VB_Windows_Store_App.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:VB_Windows_Store_App"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">
    <Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
        <Button Content="Button" Name="btnSend"
          HorizontalAlignment="Left" Height="42" Margin="397,140,0,0" VerticalAlignment="Top" Width="194"/>
        <TextBlock  Name="textStatus"
            HorizontalAlignment="Left" Height="46" Margin="454,248,0,0"
                    TextWrapping="Wrap" Text="TextBlock" VerticalAlignment="Top" Width="265"/>
    </Grid>
</Page>

Install-Package EASendMail

Add Reference¶

To use EASendMail SMTP Component in your Windows Store App/UWP project, the first step is “Add reference of EASendMail to your project”. Please create/open your project with Visual Studio, then select menu -> Project -> Add Reference -> Browse -> Browse..., and select the Installation Path\Lib\[portable/uap]\EASendMail.winmd from local disk, click Open -> OK, the reference will be added to your project, and you can start to use EASendMail SMTP Component in your project.

Public NotInheritable Class MainPage
    Inherits Page

    Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)

    End Sub
    Private Sub btnSend_Click(sender As Object, e As RoutedEventArgs) Handles btnSend.Click
    End Sub
End Class

' Add EASendMail and Tasks Namespace
Imports EASendMail
Imports System.Threading.Tasks

Public NotInheritable Class MainPage
    Inherits Page

    Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)

    End Sub

    Private Async Function btnSend_Click(sender As Object, e As RoutedEventArgs) _
        As Task Handles btnSend.Click
        btnSend.IsEnabled = False
        Await Send_Email()
        btnSend.IsEnabled = True

    End Function

    Private Async Function Send_Email() As Task
        Dim Result As String = ""
        Try

            Dim oMail As New SmtpMail("TryIt")

            ' Set sender email address, please change it to yours
            oMail.From = New MailAddress("test@emailarchitect.net")

            ' Add recipient email address, please change it to yours
            oMail.To.Add(New MailAddress("support@emailarchitect.net"))

            ' Set email subject
            oMail.Subject = "test email from VB XAML project"

            ' Set email body
            oMail.TextBody = "this is a test email sent from Windows Store App, do not reply"

            ' Your SMTP server address
            Dim oServer As New SmtpServer("smtp.emailarchitect.net")

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

            ' If your SMTP server requires TLS connection on 25 port, please add this line
            ' oServer.ConnectType = SmtpConnectType.ConnectSSLAuto

            ' If your SMTP server requires SSL connection on 465 port, please add this line
            ' oServer.Port = 465
            ' oServer.ConnectType = SmtpConnectType.ConnectSSLAuto

            Dim oSmtp As New SmtpClient()

            Await oSmtp.SendMailAsync(oServer, oMail)
            Result = "Email was sent successfully!"

        Catch ep As Exception
            Result = String.Format("Failed to send email with the following error: {0}", ep.Message)
        End Try

        ' Display Result by Diaglog box
        Dim dlg As New Windows.UI.Popups.MessageDialog(Result)
        Await dlg.ShowAsync()
    End Function
End Class

Common SMTP Transport Error¶

When you execute above example code, if it threw an exception about “Networking connection” or “No such host”, it is likely that your SMTP server address is not correct. If it threw an exception about “5xx Relay denied”, it is likely that you did not set user authentication. Another common error is “5xx Must issue a STARTTLS command first” or “No supported authentication marshal found!”, that is because your SMTP server requires user authentication under SSL connection. You can set the SSL connection to solve this problem. You can learn more detail in Troubleshooting section.

Where can I get my SMTP email server address, user and password?¶

Because each email account provider has different server address, so you should query your SMTP server address from your email account provider. To prevent spreading email from the server, most SMTP servers also require user authentication. User name is your email address or your email address without domain part, it depends on your email provider setting.

When you execute above example code, if you get error about “Networking connection” or “No such host”, it is likely that your SMTP server address is not correct. If you get an error like “5xx Relay denied”, it is likely that you did not set user authentication. Another common error is “5xx Must issue a STARTTLS command first” or “No supported authentication marshal found!”, that is because your SMTP server requires user authentication under SSL connection. You can set the SSL connection to solve this problem.

Finally, if you have already set your account in your email client such as Outlook or Window Mail, you can query your SMTP server address, user in your email client. For example, you can choose menu -> “Tools” - > - “Accounts” - > “Your email account” - > “Properties” - > “Servers” in Outlook express or Windows Mail to get your SMTP server, user. Using EASendMail to send email does not require you have email client installed on your machine or MAPI, however you can query your exist email accounts in your email client.

Email Address Syntax and Multiple Recipients¶

The following example codes demonstrates how to specify display name and email address by different syntax.

' For single email address (From, ReplyTo, ReturnPath), the syntax can be:
' ["][display name]["]<email address>
'  For example:
"Tester, T" <test@adminsystem.com>
Tester <test@adminsystem.com>
<test@adminsystem.com>
test@adminsystem.com

' For mulitple email address (To, CC, Bcc), the syntax can be:
' [single email],[single email]...
' (,;\r\n) can be used to separate multiple email addresses.
' For example:
"Tester, T" <test1@adminsystem.com>, Tester2 <test2@adminsystem.com>,
    <test3@adminsystem.com>, test4@adminsystem.com

[VB - Email syntax]

To better understand the email address syntax, please refer to the following codes.

oMail.From = New MailAddress( "Tester", "test@adminsystem.com" )
oMail.From = New MailAddress( "Tester<test@adminsystem.com>")
oMail.From = New MailAddress( "test@adminsystem.com" )

oMail.To = New AddressCollection( "test1@adminsystem.com, test2@adminsystem.com" )
oMail.To = New AddressCollection( "Test1<test@adminsystem.com>, Test2<test2@adminsystem.com>")
oMail.To.Add( New MailAddress( "tester", "test@adminsystem.com"))

oMail.Cc.Add( New MailAddress( "CC recipient", "cc@adminsystem.com"))
oMail.Bcc.Add( New MailAddress( "Bcc recipient", "bcc@adminsystem.com"))

From, ReplyTo, Sender and Return-Path¶

From, Reply-To, Sender and Return-Path are common email headers in email message. You should always set From property at first, it is a MUST to identify the email sender. The following table lists the header and corresponding properties:

• From

  This property indicates the original email sender. This is what you see as the “FROM” in most mail clients.

• Reply-To

  This property indicates the reply address. Basically, when the user clicks “reply” in mail client, the Reply-To value should be used as the recpient address of the replied email. If you don’t set this property, the Reply address is same as From address.

• Sender

  This property indicates the who submit/send the email. When the user received the email, the email client displays: From: “sender address” on behalf of “from address”. If you don’t set this property, the Sender address is same as From address. Sender property is common used by mail listing provider. This property also takes effect to DKIM/DomainKeys signature, if Sender is different with From address, then you should sign DKIM/DomainKeys based on Sender domain instead of From address domain.

• Return-Path

  This property indicates the delivery notification report address. If you don’t set this property, the Return-Path address is same as From address. This property also takes effect to SPF record, if Return-Path is different with From address, then remote SMTP server checkes SPF record of Return-Path instead of From address.

[VB.NET - From, ReplyTo, Sender and Return-Path in Email - Example]

The following example codes demonstrate how to specify From, Reply-To, Sender and Return-Path in Email. With the following example codes:

• If the email couldn’t be delivered to recipient, a non-delivery report will be sent to report@emailarchitect.net.
• If the user received the email, the email client will display: sender@emailarchitect.net on behalf of from@adminsystem.com.
• If the user click “reply”, the replied email will be sent to reply@adminsystem.com.

Dim oMail As New SmtpMail("TryIt")
oMail.From = "from@adminsystem.com"
oMail.ReplyTo = "reply@adminsystem.com"
oMail.Sender = "sender@emailarchitect.net"
oMail.ReturnPath = "report@emailarchitect.net"

Mail Priority¶

If you want to set Higher or Lower priority to your email, you can use Priority prority

[VB - Mail Priority - Example]

' Set high priority
oMail.Priority = MailPriority.High

Troubleshooting¶

When you send email in above simple VB project, if it threw an exception, please have a look at the following tips:

Using Telnet to detect networking connection to SMTP server¶

Note

Notice: in Windows 2008/Windows 8 or later version, Telnet Client is not installed by default, you should enable this command in Control Panel -> Programs and Features -> Turn Windows feature on or off -> have Telnet Client checked.

Under DOS command prompt, input “telnet [serveraddress] [port]”:

telnet mail.emailarchitect.net 25
press enter.

If the networking connection to your SMTP server is good, it should return a message like 220 .... If it returns Could not open connection to ..., that means the networking connection to SMTP server is bad, or outbound 25 port is blocked by anti-virus software, firewall or ISP. Please have a look at the following screenshot:

' If your smtp server requires TLS connection, please add this line
oServer.ConnectType = SmtpConnectType.ConnectSSLAuto

Try
    ' add this line here to generate log file
    oSmtp.LogFileName = "ms-appdata:///local/smtp.txt"
    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