Send Email in VB 6.0 - Tutorial¶

Send email in a simple VB6 project using SMTP protocol¶

To better demonstrate how to send email using SMTP protocol, let’s create a VB 6.0 Standard EXE project at first, then add a CommandButton on the Form, double-click this button. It is like this:

Add Reference¶

To use EASendMail SMTP ActiveX Object in your project, the first step is “Add reference of EASendMail to your project”. Please select menu -> Project -> References -> and select EASendMailObj ActiveX Object, click OK, the reference will be added to current project, and you can start to use it to send email in your project.

Const ConnectNormal = 0
Const ConnectSSLAuto = 1
Const ConnectSTARTTLS = 2
Const ConnectDirectSSL = 3
Const ConnectTryTLS = 4

Private Sub Command1_Click()

    Dim oSmtp As New EASendMailObjLib.Mail
    oSmtp.LicenseCode = "TryIt"

    ' Set your sender email address
    oSmtp.FromAddr = "test@emailarchitect.net"
    ' Add recipient email address
    oSmtp.AddRecipientEx "support@emailarchitect.net", 0

    ' Set email subject
    oSmtp.Subject = "simple email from VB 6.0 project"
    ' Set email body
    oSmtp.BodyText = "this is a test email sent from VB 6.0 project, do not reply"

    ' Your SMTP server address
    oSmtp.ServerAddr = "smtp.emailarchitect.net"

    ' User and password for ESMTP authentication, if your server doesn't require
    ' User authentication, please remove the following codes.
    oSmtp.UserName = "test@emailarchitect.net"
    oSmtp.Password = "testpassword"

    ' ConnectTryTLS means if server supports SSL/TLS connection, SSL/TLS is used automatically
    oSmtp.ConnectType = ConnectTryTLS

    ' If your server uses 587 port
    ' oSmtp.ServerPort = 587

    ' If your server uses 25/587/465 port with SSL/TLS
    ' oSmtp.ConnectType = ConnectSSLAuto
    ' oSmtp.ServerPort = 25 ' 25 or 587 or 465

    MsgBox "start to send email ..."
    If oSmtp.SendMail() = 0 Then
        MsgBox "email was sent successfully!"
    Else
        MsgBox "failed to send email with the following error:" & oSmtp.GetLastErrDescription()
    End If

End Sub

Common SMTP Transport Error¶

When you execute above example code, if it returned an error about “Networking connection/Socket” 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.

TLS 1.2¶

TLS is the successor of SSL, more and more SMTP servers require TLS 1.2 encryption now.

If your operating system is Windows XP/Vista/Windows 7/Windows 2003/2008/2008 R2/2012/2012 R2, and you got connection error with SSL/TLS connection, you need to enable TLS 1.2 protocol in your operating system like this:

Enable TLS 1.2 on Windows XP/Vista/7/10/Windows 2008/2008 R2/2012

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.

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 6.0 - Email syntax - Example]

To better understand the email address syntax, please refer to the following codes. It demonstrate how to specify from, to, cc by different email address syntax.

oSmtp.FromAddr = "Tester<test@adminsystem.com>"
oSmtp.FromAddr = "test@adminsystem.com"
oSmtp.FromAddr = "<test@adminsystem.com>"

' Using AddRecipientEx to add To, Cc and Bcc in VB 6.0/Visual Basic 6.0
' Multiple addresses are separated with (,)
' The syntax is like this: "test@adminsystem.com, test1@adminsystem.com"
oSmtp.AddRecipientEx "test1@adminsystem.com, test2@adminsystem.com", 0
oSmtp.AddRecipientEx "Test1<test@adminsystem.com>, Test2<test2@adminsystem.com>", 0

' You can also add carbon copy (CC) or blind carbon copy (BCC) in the email.
oSmtp.AddRecipientEx "CC recipient<cc@adminsystem.com>", 1
oSmtp.AddRecipientEx "Bcc recipient<bcc@adminsystem.com>", 2

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 6.0 - 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.

' [VB, VBA - From, ReplyTo, Sender and Return-Path]
Dim oSmtp As New EASendMailObjLib.Mail
oSmtp.LicenseCode = "TryIt"
oSmtp.FromAddr = "from@adminsystem.com"
oSmtp.ReplyTo = "reply@adminsystem.com"
oSmtp.Sender = "sender@emailarchitect.net"
oSmtp.ReturnPath = "report@emailarchitect.net"

'[VBScript, ASP - From, ReplyTo, Sender and Return-Path]
Dim oSmtp
Set oSmtp = Server.CreateObject("EASendMailObj.Mail")
oSmtp.LicenseCode = "TryIt"
oSmtp.FromAddr = "from@adminsystem.com"
oSmtp.ReplyTo = "reply@adminsystem.com"
oSmtp.Sender = "sender@emailarchitect.net"
oSmtp.ReturnPath = "report@emailarchitect.net"

Mail Priority¶

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

[VB 6.0 - Mail Priority - Example]

' Set high priority
oSmtp.Priority = 1 'High priority

Troubleshooting¶

When you send email in above simple VB project, if it returned an error, 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
oSmtp.ConnectType = 1

oSmtp.LogFileName = "d:\smtp.txt"

Process Bounced Email (Non-Delivery Report)¶

If you sent email successfully without error, that means the email has been submitted to the SMTP server. The SMTP server will deliver the email in background, if the email couldn’t be delivered, a Failure Report (NDS) will be sent back to your sender email address.

To retrieve and parse Failure Report (NDS), you should monitor your sender mailbox. I recommend that you use EAGetMail to monitor your sender mailbox using POP3/IMAP4/Exchange WebDAV/Exchange Web Service protocol. After you installed EAGetMail on your machine, there are several full samples named “parse_report.*” for VB6, Delphi, Visual C++ in the installation path.

Email Tracking¶

Email tracking is used to verify that emails are actually read by recipients. There are two common solutions: Read Receipt and Linked Image Tracking

To learn more detail about Process Bounced Email (Non-Delivery Report) and Email Tracking, please have a look at this topic: Process Bounced Email (Non-Delivery Report) and Email Tracking

Bulk Email Sender Guidelines¶

If you are a mail listing provider and send bulk emails every day, of course you don’t want your emails are blocked or moved to Junk folder of the recipient mailbox.

To increase the inbox delivery rate of your messages, make sure that all recipients on your distribution lists actually want to receive the mail. Have a look the topic for some tips on how to make sure your messages are welcomed by most email providers:

Bulk Email Sender Guidelines

32bit/x64 ActiveX DLL¶

Seperate builds of run-time dll for 32 and x64 platform

Distribution¶

• Standard EXE

  For VB6, C++, Delphi or other standard exe application, you can distribute EASendMailObj.dll with your application to target machine without COM-registration and installer. To learn more detail, please have a look at Registration-free COM with Manifest File.

• Script

  For ASP, VBScript, VBA, MS SQL Stored Procedure, you need to install EASendMail on target machine by EASendMail installer, both 32bit/x64 DLL are installed and registered.

Next Section

In this section, I introduced how to send email in a simple VB6 project using SMTP protocol. At next section I will introduce how to send email over SSL/TLS connection in VB 6.0.