In previous section, I introduced how to verify digital signature and decrypt email. In this section, I will introduce how to parse winmail.dat (TNEF stream) in VB.NET.
Sections:
When an Outlook user composes and sends a message using either Rich Text Format or HTML Format, Outlook automagically generates a file, winmail.dat, and attaches it to the end of the email. The winmail.dat contains the rich text body and original attachments. To parse winmail.dat (TNEF stream) file, we should use ParseTNEF method.
Note
Remarks: All of examples in this section are based on first section: A simple VB.NET project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference to your project.
The following example codes demonstrate how to parse MAPI winmail.dat.
Note
To get the full sample projects, please refer to Samples section.
Imports System.Globalization
Imports System.Text
Imports System.IO
Imports EAGetMail 'imports EAGetMail namespace
Module Module1
Private Sub ParseEmail(ByVal emlFile As String)
Dim oMail As New Mail("TryIt")
oMail.Load(emlFile, False)
If oMail.IsEncrypted Then
Try
' This email is encrypted, we decrypt it by user default certificate.
' you can also use specified certificate like this
' Dim oCert As New Certificate()
' oCert.Load("c:\test.pfx", "pfxpassword", _
' Certificate.CertificateKeyLocation.CRYPT_USER_KEYSET)
' oMail = oMail.Decrypt(oCert)
oMail = oMail.Decrypt(Nothing)
Catch ep As Exception
Console.WriteLine(ep.Message)
End Try
End If
If oMail.IsSigned Then
Try
' This email is digital signed.
Dim signerCert As Certificate = oMail.VerifySignature()
' You can add the certificate to your certificate storage like this
' signerCert.AddToStore(
' Certificate.CertificateStoreLocation.CERT_SYSTEM_STORE_CURRENT_USER,
' "addressbook")
' Then you can use send the encrypted email back to this sender.
Console.WriteLine("This email contains a valid digital signature.")
Catch ep As Exception
Console.WriteLine(ep.Message)
End Try
End If
' Parse Mail From/Sender
Console.WriteLine("From: {0}", oMail.From.ToString())
' Parse Mail To/Recipient
Dim addrs As MailAddress() = oMail.[To]
For i As Integer = 0 To addrs.Length - 1
Console.WriteLine("To: {0}", addrs(i).ToString())
Next
' Parse Mail CC
addrs = oMail.Cc
For i As Integer = 0 To addrs.Length - 1
Console.WriteLine("To: {0}", addrs(i).ToString())
Next
' Parse Mail Subject
Console.WriteLine("Subject: {0}", oMail.Subject)
' Parse Mail Text/Plain body
Console.WriteLine("TextBody: {0}", oMail.TextBody)
' Parse Mail Html Body
Console.WriteLine("HtmlBody: {0}", oMail.HtmlBody)
' Parse Attachments
Dim atts As Attachment() = oMail.Attachments
For i As Integer = 0 To atts.Length - 1
Dim att As Attachment = atts(i)
Console.WriteLine("Attachment: {0}", att.Name)
' This attachment is in OUTLOOK RTF format(TNEF), decode it here.
If String.Compare(att.Name, "winmail.dat", True) = 0 Then
Dim tatts As Attachment() = Nothing
Try
tatts = Mail.ParseTNEF(att.Content, True)
Catch ep As Exception
Console.WriteLine(ep.Message)
End Try
Dim y As Integer = tatts.Length
For x As Integer = 0 To y - 1
Dim tatt As Attachment = tatts(x)
Console.WriteLine("winmail.dat: {0}", tatt.Name)
Next
End If
Next
End Sub
Sub Main()
Try
ParseEmail("c:\my folder\test.eml")
Catch ex As Exception
Console.WriteLine(ex.Message)
End Try
End Sub
End Module
In EAGetMail 4.5, a new method named DecodeTNEF is introduced. It is easier to parse TNEF attachment. Please have a look at the following example codes:
Imports System.Globalization
Imports System.Text
Imports System.IO
Imports EAGetMail 'imports EAGetMail namespace
Module Module1
Private Sub ParseEmail(ByVal emlFile As String)
Dim oMail As New Mail("TryIt")
oMail.Load(emlFile, False)
If oMail.IsEncrypted Then
Try
' This email is encrypted, we decrypt it by user default certificate.
' you can also use specified certificate like this
' Dim oCert As New Certificate()
' oCert.Load("c:\test.pfx", "pfxpassword", _
' Certificate.CertificateKeyLocation.CRYPT_USER_KEYSET)
' oMail = oMail.Decrypt(oCert)
oMail = oMail.Decrypt(Nothing)
Catch ep As Exception
Console.WriteLine(ep.Message)
End Try
End If
If oMail.IsSigned Then
Try
' This email is digital signed.
Dim signerCert As Certificate = oMail.VerifySignature()
' You can add the certificate to your certificate storage like this
' signerCert.AddToStore(
' Certificate.CertificateStoreLocation.CERT_SYSTEM_STORE_CURRENT_USER,
' "addressbook")
' Then you can use send the encrypted email back to this sender.
Console.WriteLine("This email contains a valid digital signature.")
Catch ep As Exception
Console.WriteLine(ep.Message)
End Try
End If
' Decode winmail.dat (TNEF) and RTF body automatically
oMail.DecodeTNEF()
' Parse Mail From/Sender
Console.WriteLine("From: {0}", oMail.From.ToString())
' Parse Mail To/Recipient
Dim addrs As MailAddress() = oMail.[To]
For i As Integer = 0 To addrs.Length - 1
Console.WriteLine("To: {0}", addrs(i).ToString())
Next
' Parse Mail CC
addrs = oMail.Cc
For i As Integer = 0 To addrs.Length - 1
Console.WriteLine("To: {0}", addrs(i).ToString())
Next
' Parse Mail Subject
Console.WriteLine("Subject: {0}", oMail.Subject)
' Parse Mail Text/Plain body
Console.WriteLine("TextBody: {0}", oMail.TextBody)
' Parse Mail Html Body
Console.WriteLine("HtmlBody: {0}", oMail.HtmlBody)
' Parse Attachments
Dim atts As Attachment() = oMail.Attachments
For i As Integer = 0 To atts.Length - 1
Dim att As Attachment = atts(i)
Console.WriteLine("Attachment: {0}", att.Name)
Next
End Sub
Sub Main()
Try
ParseEmail("c:\my folder\test.eml")
Catch ex As Exception
Console.WriteLine(ex.Message)
End Try
End Sub
End Module
Next Section
At next section I will introduce how to convert email to HTML page and display it in Web browser.
Appendix
Comments
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